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 A115396 #5 Jul 14 2025 17:11:13 %S A115396 23,29,71,17,59,37,71,41,67,71,43,109,59,67,173,83,89,151,103,89,127, %T A115396 101,131,113,127,109,131,113,127,193,157,157,181,179,229,163,193,191, %U A115396 211,223,223,239,241,211,211,211,271,281,241,241,263,307,307,373,293 %N A115396 Smallest prime p such that p+-2n are semiprimes. %C A115396 Cf. A063643 Primes p such that p+-2 are semiprimes, A117328 Primes p such that p+-4 are semiprimes. %e A115396 a(100)=571 because 571-2*100=371=7*53 (semiprime), 571+2*100=771=3*257 (semiprime). %Y A115396 Cf. A063643. %K A115396 nonn %O A115396 1,1 %A A115396 _Zak Seidov_, Mar 08 2006