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 A087651 #10 Mar 19 2025 15:41:27 %S A087651 2,6,6,6,30,30,30,30,210,210,2310,2310,2310,2310,30030,30030,30030, %T A087651 30030,30030,30030,510510,510510,9699690,223092870,223092870, %U A087651 223092870,223092870,223092870,223092870,223092870,6469693230,200560490130 %N A087651 Sequence of primorials P# (cf. A002110) such that j*P# has twin prime neighbors for some j with 0 < j < prime following P. %C A087651 I think I have found a proof that the sequence is infinite. %e A087651 I have found the first 122 values of this sequence, 121 and 122 are 2557#, 2557# with j=303 and j=2307, 1087 and 1088 digits. %Y A087651 The j values are in A087730, P values are in A087731, i values are in A088676. %Y A087651 Cf. A002110, A086916, A087732. %Y A087651 Smaller of twin primes are in A087732. Number of digits in twin primes are in A086916. %K A087651 nonn %O A087651 0,1 %A A087651 _Pierre CAMI_, Sep 28 2003 %E A087651 Edited by _Jud McCranie_ and _Ray Chandler_, Oct 05 2003