This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A227756 #12 Apr 18 2025 08:54:17 %S A227756 23,29,41,53,101,113,137,173,257,281,317,353,401,617,641,653,677,761, %T A227756 821,941,977,1181,1193,1361,1373,1433,1613,1697,1877,1901,2081,2153, %U A227756 2237,2273,2297,2333,2381,2633,2657,2693,2741,2777,2801,3137,3413,3461,3557 %N A227756 Primes p such that antisigma(p) = antisigma(p+1) + 12, where antisigma = A024816. %C A227756 Primes p such that sigma(p + 1) = 2*p + 14. %C A227756 This is the subsequence of primes in A227757. %C A227756 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,... %H A227756 Jaroslav Krizek, <a href="/A227756/b227756.txt">Table of n, a(n) for n = 1..500</a> %e A227756 The prime 41 is in sequence because antisigma(41) = 819 = antisigma(42) + 12 = 807 + 12. %t A227756 Select[Prime[Range[500]],DivisorSigma[1,# + 1] == 2*# + 14 &] (* _Stefano Spezia_, Apr 18 2025 *) %Y A227756 Cf. A024816, A227757, A051027. %K A227756 nonn %O A227756 1,1 %A A227756 _Jaroslav Krizek_, Jul 26 2013