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 A258860 #4 Jun 12 2015 20:47:53 %S A258860 0,0,0,0,4,0,4,4,622592,622592,0,0,4931584,4,2304,12288,38944768,4, %T A258860 12288,81920,38944768,2304,512,81920,714096,81920,12288,65719296, %U A258860 2298880,0,622592,0,278380544,81920,0,4,85988,622592,4,2298880,85988,4,208,512,13319168 %N A258860 Tenth pi-based arithmetic derivative of n. %H A258860 Alois P. Heinz, <a href="/A258860/b258860.txt">Table of n, a(n) for n = 0..10000</a> %F A258860 a(n) = A258851^10(n). %p A258860 with(numtheory): %p A258860 d:= n-> n*add(i[2]*pi(i[1])/i[1], i=ifactors(n)[2]): %p A258860 A:= proc(n, k) option remember; `if`(k=0, n, d(A(n, k-1))) end: %p A258860 a:= n-> A(n, 10): %p A258860 seq(a(n), n=0..100); %Y A258860 Column k=10 of A258850. %Y A258860 Cf. A000720, A258851. %K A258860 nonn %O A258860 0,5 %A A258860 _Alois P. Heinz_, Jun 12 2015