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 A301750 #6 Mar 26 2018 20:02:27 %S A301750 1,1,2,3,5,8,12,18,29,42,61,86,127,181,257,352,489,668,935,1270,1730, %T A301750 2312,3101,4112,5533,7345,9742,12785,16793,21821,28452,36908,48108, %U A301750 62198,80337,103081,132372,168805,215247,273678 %N A301750 Number of rooted twice-partitions of n where the composite rooted partition is strict. %C A301750 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. %e A301750 The a(8) = 18 rooted twice-partitions where the composite rooted partition is strict: %e A301750 (6), (51), (42), (321), %e A301750 (5)(), (41)(), (32)(), (4)(1), (3)(2), %e A301750 (4)()(), (31)()(), (3)(1)(), %e A301750 (3)()()(), (21)()()(), (2)(1)()(), %e A301750 (2)()()()(), %e A301750 (1)()()()()(), %e A301750 ()()()()()()(). %t A301750 twirtns[n_]:=Join@@Table[Tuples[IntegerPartitions[#-1]&/@ptn],{ptn,IntegerPartitions[n-1]}]; %t A301750 Table[Select[twirtns[n],UnsameQ@@Join@@#&]//Length,{n,30}] %Y A301750 Cf. A002865, A063834, A093637, A127524, A279790, A294788, A301422, A301462, A301467, A301480, A301706. %K A301750 nonn %O A301750 1,3 %A A301750 _Gus Wiseman_, Mar 26 2018