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 A301760 #6 Mar 26 2018 20:03:03
%S A301760 1,1,2,4,7,11,17,24,34,46,63,82,109,140,183,233,298,376,479,598,753,
%T A301760 938,1171,1449,1797,2210,2726,3342,4095,4990,6088,7388,8968,10843,
%U A301760 13099,15770,18975,22756,27276,32603,38925,46353,55158,65479,77656,91904,108645
%N A301760 Number of rooted twice-partitions of n where the composite rooted partition is constant.
%C A301760 A rooted partition of n is an integer partition of n - 1. A rooted twice-partition of n is a choice of a rooted partition of each part in a rooted partition of n.
%F A301760 O.g.f.: 1/(1 - x) + Sum_{n > 0} (-1/(1 - x) + Product_{k >= 0} 1/(1 - x^(n * k + 1))).
%e A301760 The a(5) = 7 rooted twice-partitions: (3), (111), (2)(), (11)(), (1)(1), (1)()(), ()()()().
%t A301760 nn=50;
%t A301760 ser=(1-nn)/(1-x)+Sum[Product[1/(1-x^(d k+1)),{k,0,nn}],{d,nn}];
%t A301760 CoefficientList[Series[ser,{x,0,nn}],x]
%Y A301760 Cf. A002865, A047968, A063834, A093637, A295924, A301422, A301462, A301467, A301480, A301706.
%K A301760 nonn
%O A301760 1,3
%A A301760 _Gus Wiseman_, Mar 26 2018