A227756 Primes p such that antisigma(p) = antisigma(p+1) + 12, where antisigma = A024816.

23, 29, 41, 53, 101, 113, 137, 173, 257, 281, 317, 353, 401, 617, 641, 653, 677, 761, 821, 941, 977, 1181, 1193, 1361, 1373, 1433, 1613, 1697, 1877, 1901, 2081, 2153, 2237, 2273, 2297, 2333, 2381, 2633, 2657, 2693, 2741, 2777, 2801, 3137, 3413, 3461, 3557

Offset

1,1

Comments

Primes p such that sigma(p + 1) = 2*p + 14.

This is the subsequence of primes in A227757.

Also primes p such that sigma(sigma(p)) - sigma(p) - p = 13 (see A227758). The composite numbers with this property are 333, 37377, 972691, 1089871,...

Links

Jaroslav Krizek, Table of n, a(n) for n = 1..500

Example

The prime 41 is in sequence because antisigma(41) = 819 = antisigma(42) + 12 = 807 + 12.

Mathematica

Select[Prime[Range[500]], DivisorSigma[1, # + 1] == 2*# + 14 &] (* Stefano Spezia, Apr 18 2025 *)

Crossrefs

Cf. A024816, A227757, A051027.

Sequence in context: A162658 A303009 A227757 * A007637 A161723 A085448

Adjacent sequences: A227753 A227754 A227755 * A227757 A227758 A227759

Keyword

nonn

Author

Jaroslav Krizek, Jul 26 2013

Status

approved