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 A257554 #16 Aug 24 2021 10:14:57 %S A257554 1,2,3,4,5,6,7,8,9,36,128,175,384,735,1296,2916,18432,34992,82944, %T A257554 139968,442368,2333772,4128768,9289728,12192768,13226976,13395375, %U A257554 13436928,27869184,49787136,376233984,429981696,1269789696,2633637888,4161798144,16728477696,19999187712,41479796736,72236924928 %N A257554 Numbers k such that A007954(k) divides k and k divides A007954(k)^2. %C A257554 There are 66 terms below 10^400 with the largest containing 46 digits. %H A257554 Max Alekseyev, <a href="/A257554/b257554.txt">Table of n, a(n) for n = 1..66</a> %o A257554 (PARI) for(n=1,10^6, d=digits(n); p=prod(i=1,#d,d[i]); if(p && n%p==0 && p^2%n==0, print1(n,", ") )) \\ _Derek Orr_, Apr 29 2015 %Y A257554 Intersection of A007602 and A128606. %K A257554 nonn,base %O A257554 1,2 %A A257554 _Max Alekseyev_, Apr 29 2015