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 A209395 #11 Jul 11 2023 07:59:41 %S A209395 4224533,5903497,16462297,22028203,44068001,336273211,1067437801, %T A209395 1813073653,1876485691,1894909141,2072488771,2458231903,2791053541, %U A209395 2827961221,3733646491,4333572253 %N A209395 Strong pseudoprimes to bases 19, 23 and 29. %C A209395 Intersection of A020245, A020249 and A020255. %o A209395 (PARI) /* see A001262, A020237, A020239 */ %Y A209395 Cf. A074773, A188755. %K A209395 nonn %O A209395 1,1 %A A209395 _R. J. Mathar_, Mar 07 2012