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 A090264 #7 Dec 20 2019 11:13:17 %S A090264 131,153,191,233,261,327,341,359,389,407,429,459,489,527,533,579,593, %T A090264 599,671,683,701,723,731,797,813,869,873,939,981,1083,1097,1109,1143, %U A090264 1187,1241,1283,1317,1391,1437,1451,1539,1553,1871,1889,1893,2049,2111 %N A090264 Numbers n such that the strings n7n and 7n7 are both prime. %H A090264 Daniel Starodubtsev, <a href="/A090264/b090264.txt">Table of n, a(n) for n = 1..10000</a> %e A090264 131 is a member as 1317131 and 71317 are both prime. %Y A090264 Cf. A090262, A090263, A090265. %K A090264 base,nonn %O A090264 1,1 %A A090264 _Amarnath Murthy_, Nov 28 2003 %E A090264 More terms from mohammed bouayoun (bouyao(AT)wanadoo.fr), Feb 02 2004