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 A171821 #19 Mar 28 2017 14:42:03 %S A171821 2,3,5,7,11,13,17,19,29,31,41,43,59,61,71,73,101,103,107,109,137,139, %T A171821 149,151,179,181,191,193,197,199,227,229,239,241,269,271,281,283,311, %U A171821 313,347,349,419,421,431,433,461,463,521,523,569,571,599,601,617,619,641 %N A171821 2 together with twin primes. %C A171821 Primes of the form p-1, p-2 and p+2 for p prime. - _Juri-Stepan Gerasimov_, Apr 30 2010 %C A171821 Numbers n such that A283265(n) = 0. - _Mats Granvik_, Mar 18 2017 %H A171821 Michael De Vlieger, <a href="/A171821/b171821.txt">Table of n, a(n) for n = 1..10000</a> %t A171821 Union@ Flatten@ Select[Partition[#, 2, 1] &@ Prime@ Range@ 117, First@ Differences@ # <= 2 &] (* _Michael De Vlieger_, Mar 18 2017 *) %Y A171821 Cf. A001097(twin primes), A283265. %K A171821 nonn %O A171821 1,1 %A A171821 _Juri-Stepan Gerasimov_, Dec 19 2009 %E A171821 Entries checked by _D. S. McNeil_, Nov 26 2010