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 A112880 #5 Jun 20 2021 09:40:19 %S A112880 12,18,492,702,2310,2370,130650,980910,5528418,21357012 %N A112880 The factors k(n) such that the twin-prime subsequence A112879 is obtained. %e A112880 12*3^2-1=107, 107 and 109 twin primes so k(1)=12 %e A112880 18*107^2-1=206081, 206081 and 206083 twin primes so k(2)=18 %Y A112880 Cf. A112879. %K A112880 hard,nonn %O A112880 1,1 %A A112880 _Pierre CAMI_, Oct 01 2005 %E A112880 Removed misleading mention of a(n) in NAME. - _R. J. Mathar_, Jun 20 2021