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 A276836 #9 Oct 21 2016 15:16:02
%S A276836 1,1,1,1,1,2,1,3,1,4,3,5,1,6,1,7,15,2,1,9,1,5,21,11,1,2,5,13,9,7,1,15,
%T A276836 1,8,11,17,35,27,1,19,39,5,1,7,1,44,45,69,1,54,7,125,17,39,1,27,55,14,
%U A276836 57,116
%N A276836 Denominator of modified von Mangoldt function defined recursively.
%C A276836 See A276835 for the conjecture about the ratio A276835(n)/A276836(n).
%F A276836 Recurrence for the ratio A276835(n)/A276836(n):
%F A276836 t(1, 1) = 1, t(n, k) = if(n/k = 2 then 2 else if(and(k == 1, n >= 3), n/(Product_{i = 1..n-1} t(n, k + i))/(Product_{i = 1..n-1} t(n, k + i)) else if(mod(n, k) = 0 then t(n/k, 1) else 1) else 1)).
%t A276836 Clear[t]; nn = 60; t[1, 1] = 1; t[n_, k_] := t[n, k] = If[n/k == 2, 2, If[And[k == 1, n >= 3], n/Product[t[n, k + i], {i, 1, n - 1}]/Product[t[n - 2, k + i], {i, 1, n - 1}],If[Mod[n, k] == 0, t[n/k, 1], 1], 1]]; a = Table[t[n, 1], {n, 1, nn}]; Numerator[a]; Denominator[a]
%Y A276836 Cf. A276835, A006512, A014963.
%K A276836 nonn,frac,more
%O A276836 1,6
%A A276836 _Mats Granvik_, Sep 20 2016