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 A258646 #4 Jun 07 2015 07:26:52 %S A258646 0,0,0,0,4,0,0,0,368,0,0,0,752,0,0,176,1520,0,0,0,608,0,0,0,1552,0,80, %T A258646 27,1520,0,0,0,3424,0,0,368,1312,0,0,752,288,0,0,0,3120,368,0,0,8144, %U A258646 0,176,240,1312,0,2484,752,3312,0,0,0,3312,0,1,112,245760,0 %N A258646 Sixth arithmetic derivative of n. %H A258646 Alois P. Heinz, <a href="/A258646/b258646.txt">Table of n, a(n) for n = 0..10000</a> %F A258646 a(n) = A003415^6(n). %p A258646 d:= n-> n*add(i[2]/i[1], i=ifactors(n)[2]): %p A258646 A:= proc(n, k) option remember; `if`(k=0, n, d(A(n, k-1))) end: %p A258646 a:= n-> A(n, 6): %p A258646 seq(a(n), n=0..70); %Y A258646 Column k=6 of A258651. %Y A258646 Cf. A003415. %K A258646 nonn %O A258646 0,5 %A A258646 _Alois P. Heinz_, Jun 06 2015