Voodooguru

"There are things that drift away, like our endless numbered days" from Iron & Wine's Passing Afternoon

[Voodooguru @SeanReeves]

28229: prime

110^2+127^2; member of OEIS A000230: a(0)=2 and, for n>=1, a(n) = smallest prime p s.t. there is a gap of exactly 2n between p and next prime, here n=24; xenodrome in base 8: 67105.

https://t.co/0rV4lzsjl9

[Voodooguru @SeanReeves]

28228: 2^2 * 7057

2^2+168^2; member of OEIS A048381: numbers s.t. replacing each nonzero digit d with d-th prime & each 0 digit with 1 yields a prime, here 3193319; energetic number 2^14+82^2+2^10+8^4; Loeschian number (96, 98).

https://t.co/sLTxJri2EB
https://t.co/S97yDvJfEf

[Voodooguru @SeanReeves]

28227: 3 * 97^2

Member of OEIS A247317: numbers n s.t. sum of all cyclic permutations equals all cyclic permutations of sigma(n) and all cyclic permutations of Euler totient function phi(n); Loeschian number in more than one way.

https://t.co/zQxwM2RA0J
https://t.co/5frafCoVTL

[Voodooguru @SeanReeves]

28226: 2 * 11 * 1283

Member of A048381: numbers s.t. each nonzero digit --> n-th prime and each 0 digit --> 1 yields a prime, here 3193313; Friedman number: 28226 = (28 × 6)^2 + 2; inconsummate, junction and Curzon number.

https://t.co/sLTxJri2EB
https://t.co/XzNKv4563K

[Voodooguru @SeanReeves]

28225: 5^2 * 1129

1^2+168^2, 48^2+161^2, 100^2+135^2; numbers whose sum of digits (19), sum of digits squared (101) and sum of digits cubed (661) are all prime; 49th centered 24-gonal, 50th 25-gonal number and 64th centered 14-gonal number.

https://t.co/yor8eRzmUv

[Voodooguru @SeanReeves]

28224: 2^6 * 3^2 * 7^2

168^2 = 22^3+26^3; energetic number: 28^3 + 2^11 + 2^7 + 4^6; Friedman number (2 + 82)^2 × 4; abundant, practical, gapful, interprime, junction and Harshad number; factors concatenate to 22288222.

https://t.co/XzNKv4563K

[Voodooguru @SeanReeves]

28223: 13^2 * 167

Member of OEIS OEIS A064702: numbers whose arithmetic and multiplicative digital roots are the same, here 8; Duffinian number; nialpdrome in base 13: cb00 and xenodrome in base 9: 42638l.

https://t.co/APN9UBWEit
https://t.co/vNeAJ3o5Hx

[Voodooguru @SeanReeves]

28222: 2 * 103 * 137

Reversible sphenic number since 22282 = 2 * 13 * 857; junction number since 28196 + 26 (digit sum) = 28205 + 17 (digit sum) = 28222; modest number since 28222 % 222 = 28; SOD & POD are perfect powers (16, 128)

https://t.co/x9zLdu8MSM
https://t.co/9PMI7LMXDp

[Voodooguru @SeanReeves]

28221: 3 * 23 * 409

Sphenic numbers with factors whose digital roots (3, 5 and 4) differ from one another and from the digital root (6) of the number; Curzon, self, inconsummate and 69th 14-gonal number; zero of the Mertens function.

https://t.co/qX4LSyLBZU

[Voodooguru @SeanReeves]

28220: 2^2 * 5 * 17 * 83

Reaches narcissistic number 370 under algorithm described in attached link; gapful, abundant, Zumkeller, pseudoperfect, practical and junction number; xenodrome in base 9: 42635.

https://t.co/n5aYdcOPOy

[Voodooguru @SeanReeves]

28219: prime

Member of OEIS A069686: primes whose internal digits form a prime, here 821; adding consecutive pairs of digits in base 9 produces a prime number; palindrome in base 2: 110111000111011 and base 32: rhr; self number.

https://t.co/BX0xLjcmg0
https://t.co/vapdszLb2g

[Voodooguru @SeanReeves]

28218: 2 * 3 * 4703

Member of OEIS A071927: barely abundant number n since sigma(n)/n < sigma(m)/m for all abundant number m < n: Junction Number since 28194 + 24 (digit sum) = 28218 and 28203 + 15 (digit sum) = 28218; concatenation of powers of 2.

https://t.co/EuNIZT459M

[Voodooguru @SeanReeves]

28217: 7 * 29 * 139

Sphenic number that is reversible (71282 = 2 * 29 * 1229) and also the start of a run of eight sphenic numbers derived using surface area --> volume of sphenic brick conversions; Friedman number (21*8)^2-7.

https://t.co/acg720vLAw
https://t.co/VQBkWsXtwl

[Voodooguru @SeanReeves]

28216: 2^3 * 3527

Number is a concatenation of powers of 2: 2^1 | 2^3 | 2^1 | 2^4; changing each digit d to prime(d) yields prime 3193213; junction number since 28193 + 23 (digit sum) = 28216 and 28202 + 14 (digit sum) = 28216.

https://t.co/YLw5logbGa
https://t.co/HmVXesq54v

[Voodooguru @SeanReeves]

28215: 3^3 * 5 * 11 * 19

Member of OEIS A006038: odd primitive abundant number; its totient and totient of its reversal are equal (12960); member of comma sequence starting with 8; interprime number (between 28211 and 28219).

https://t.co/BOz2QJet9Y
https://t.co/QhYIbZLIT8

[Voodooguru @SeanReeves]

28214: 2 * 14107

Number whose sum of digits (SOD), SOD^2 & SOD^3 are all prime (17, 89, 593); concatenation of powers of 2; emirpimes since 41282 = 2 * 20641; inconsummate and junction number (28192 + 22 = 28201 + 13 =28214).

https://t.co/yor8eRzmUv
https://t.co/YLw5logbGa

[Voodooguru @SeanReeves]

28213: 89 * 317

18^2+167^2 = 57^2+158^2; member of OEIS A096003: smallest semiprime k that is at the end of an arithmetic progression of n semiprimes, here n=16; cyclic, Duffinian and happy number; emirpimes since 31282 = 2 * 15641.

https://t.co/01HatfnYwQ

[Voodooguru @SeanReeves]

28212: 2^2 * 3 * 2351

Member of OEIS A028980: numbers whose sum of divisors is palindromic, here 65856; abundant and junction number since 28191 + 21 (digit sum) = 28212 and 28200 + 12 = 28212.

https://t.co/cjQIxQJz75

[Voodooguru @SeanReeves]

28211: prime

Member of OEIS A069686: primes whose internal digits form a prime, here 821 and A235000: primes which become palindromic primes when the digits are rotated once to the right, here 12821.

https://t.co/uj8z7kqCKh
https://t.co/IjzUmMYQHn

[Voodooguru @SeanReeves]

28210: 2 * 5 * 7 * 13 * 31

Member of OEIS A048381: numbers n s.t. replacing each nonzero digit d with the d-th prime and each 0 with a 1 yields a prime; cannot be rendered as a digit equation; Harshad and abundant number.

https://t.co/sLTxJri2EB
https://t.co/zzy8KacwNX