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 A339059 #7 Nov 23 2020 08:25:53 %S A339059 1,1,0,0,0,1,2,0,0,1,2,0,0,1,4,6,0,1,4,6,0,1,6,12,0,1,6,18,24,1,8,24, %T A339059 24,1,8,30,48,1,10,42,72,1,10,48,120,121,12,60,144,121,12,72,216,241, %U A339059 14,84,264,361,14,96,360,601,16,114,432,841,736,126,552,1201,738 %N A339059 Number of compositions (ordered partitions) of n into distinct parts congruent to 1 mod 4. %H A339059 <a href="/index/Com#comp">Index entries for sequences related to compositions</a> %F A339059 G.f.: Sum_{k>=0} k! * x^(k*(2*k - 1)) / Product_{j=1..k} (1 - x^(4*j)). %e A339059 a(15) = 6 because we have [9, 5, 1], [9, 1, 5], [5, 9, 1], [5, 1, 9], [1, 9, 5] and [1, 5, 9]. %t A339059 nmax = 70; CoefficientList[Series[Sum[k! x^(k (2 k - 1))/Product[1 - x^(4 j), {j, 1, k}], {k, 0, nmax}], {x, 0, nmax}], x] %Y A339059 Cf. A003269, A016813, A032020, A032021, A035451, A169975, A337547, A337548, A339060. %K A339059 nonn %O A339059 0,7 %A A339059 _Ilya Gutkovskiy_, Nov 22 2020