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 A258648 #4 Jun 07 2015 07:31:37 %S A258648 0,0,0,0,4,0,0,0,1520,0,0,0,3424,0,0,752,8592,0,0,0,3120,0,0,0,8144,0, %T A258648 368,27,8592,0,0,0,20096,0,0,1520,8976,0,0,3424,2176,0,0,0,16304,1520, %U A258648 0,0,32624,0,752,1552,8976,0,10260,3424,22288,0,0,0,22288,0,0 %N A258648 Eighth arithmetic derivative of n. %H A258648 Alois P. Heinz, <a href="/A258648/b258648.txt">Table of n, a(n) for n = 0..10000</a> %F A258648 a(n) = A003415^8(n). %p A258648 d:= n-> n*add(i[2]/i[1], i=ifactors(n)[2]): %p A258648 A:= proc(n, k) option remember; `if`(k=0, n, d(A(n, k-1))) end: %p A258648 a:= n-> A(n, 8): %p A258648 seq(a(n), n=0..70); %Y A258648 Column k=8 of A258651. %Y A258648 Cf. A003415. %K A258648 nonn %O A258648 0,5 %A A258648 _Alois P. Heinz_, Jun 06 2015