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 A048457 #6 Oct 14 2019 23:42:04 %S A048457 7,23,67,179,453,1109,2653,6231,14409,32877,74137,165429,365691, %T A048457 801747,1745331,3776605,8130401,17427659,37217597,79224121,168170537, %U A048457 356107787,752453861,1586875049,3340696135,7021048691,14731810645 %N A048457 Last odd terms from generation 2 onwards. %Y A048457 For "Generations" see A048448-A048455. See also A047844. %K A048457 nonn %O A048457 1,1 %A A048457 _Patrick De Geest_, May 15 1999