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 A101873 #11 Sep 23 2023 07:29:11 %S A101873 1,1,2,1,1,1,2,1,1,1,1,2,2,1,1,1,1,1,1,1,5,1,1,1,1,1,1,1,1,2,2,3,1,1, %T A101873 1,1,1,1,2,1,1,1,2,1,1,1,1,3,1,1,1,1,1,1,1,1,4,1,1,1,1,2,1,1,1,2,1,1, %U A101873 1,1,1,1,2,1,3,1,1,1,1,1,1,2,1,2,1,1,1,1,1,1,2,1,2,1,1,1,1,1,1,1,1,5,1,1,1 %N A101873 Number of Abelian groups of order 4n+1. %t A101873 a[n_] := FiniteAbelianGroupCount[4*n + 1]; Array[a, 100, 0] (* _Amiram Eldar_, Sep 23 2023 *) %Y A101873 Bisection of A101871. %Y A101873 Cf. A101874, A101876. %K A101873 nonn,easy %O A101873 0,3 %A A101873 _N. J. A. Sloane_, Jan 28 2005 %E A101873 More terms from _Joshua Zucker_, May 10 2006