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 A045593 #15 Aug 10 2021 04:58:40 %S A045593 1,13,169,2197,14209,28561,184717,371293,2401321,4826809,15530437, %T A045593 31217173,62748517,130238329,178895977,201895681,405823249,815730721, %U A045593 1693098277,2325647701,2422762381,2624643853,4286414821,5275702237 %N A045593 Numbers k that divide 9^k + 4^k. %Y A045593 Cf. A074608. %K A045593 nonn %O A045593 1,2 %A A045593 _David W. Wilson_