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 A069144 #10 Sep 03 2020 06:41:11 %S A069144 1,2,12,40,120,208,280,396,440,520,624,672,680,760,920,1040,1160,1240, %T A069144 1456,1480,1640,1720,1880,2120,2288,2360,2440,2680,2840,2920,3120, %U A069144 3160,3320,3360,3392,3536,3560,3880,3952,3960,4040,4120,4280,4360,4368,4520 %N A069144 Numbers k such that A068976(k) divides k. %C A069144 For n > 4 A068976(a(n)) >= 40 and almost all terms k in the sequence are such that A068976(k) = 40. %H A069144 Amiram Eldar, <a href="/A069144/b069144.txt">Table of n, a(n) for n = 1..10000</a> %t A069144 f[p_, e_] := If[OddQ[e], 2*(p^(e + 1) - 1)/(p^2 - 1), (p^(e + 2) + p^e - 2)/(p^2 - 1)]; s[1] = 1; s[n_] := Times @@ (f @@@ FactorInteger[n]); Select[Range[5000], Divisible[#, s[#]] &] (* _Amiram Eldar_, Sep 03 2020 *) %o A069144 (PARI) for(n=1,10000,if(n%sumdiv(n,d,d/core(d))==0,print1(n,","))) %Y A069144 Cf. A068976. %K A069144 easy,nonn %O A069144 1,2 %A A069144 _Benoit Cloitre_, Apr 08 2002