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 A304781 #6 May 18 2018 19:47:57
%S A304781 1,2,6,21,75,274,1016,3807,14377,54627,208584,799669,3076167,11867511,
%T A304781 45897145,177888715,690770763,2686879415,10466761637,40828165464,
%U A304781 159453481037,623427464093,2439907421914,9557831470082,37472409664888,147028505564603,577302980976146
%N A304781 a(n) = [x^n] (1/(1 - x)^n)*Product_{k>=1} (1 + x^k).
%C A304781 Number of partitions of n into odd parts with n + 1 kinds of 1.
%H A304781 <a href="/index/Par#part">Index entries for sequences related to partitions</a>
%F A304781 a(n) = [x^n] (1/(1 - x)^n)*Product_{k>=1} 1/(1 - x^(2*k-1)).
%F A304781 a(n) = [x^n] (1/(1 - x)^n)*exp(Sum_{k>=1} (-1)^(k+1)*x^k/(k*(1 - x^k))).
%F A304781 a(n) ~ QPochhammer[-1, 1/2] * 4^(n-1) / sqrt(Pi*n). - _Vaclav Kotesovec_, May 18 2018
%t A304781 Table[SeriesCoefficient[1/(1 - x)^n Product[(1 + x^k), {k, 1, n}], {x, 0, n}], {n, 0, 26}]
%t A304781 Table[SeriesCoefficient[1/(1 - x)^n Product[1/(1 - x^(2 k - 1)), {k, 1, n}], {x, 0, n}], {n, 0, 26}]
%t A304781 Table[SeriesCoefficient[1/(1 - x)^n Exp[Sum[(-1)^(k + 1) x^k/(k (1 - x^k)), {k, 1, n}]], {x, 0, n}], {n, 0, 26}]
%t A304781 Table[SeriesCoefficient[QPochhammer[-1, x]/(2 (1 - x)^n), {x, 0, n}], {n, 0, 26}]
%Y A304781 Cf. A000009, A036469, A095944, A128566, A128593, A292463, A292613, A293467.
%K A304781 nonn
%O A304781 0,2
%A A304781 _Ilya Gutkovskiy_, May 18 2018