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 A346380 #10 Jul 28 2021 14:19:03 %S A346380 0,0,1,0,3,3,18,39,157,459,1668,5503,19638,68325,245144,876438, %T A346380 3177651,11549939,42307920,155555733,574881920,2132231076,7938771624, %U A346380 29651189637,111086480106,417305224917,1571633677078,5932720163529,22443721850064,85075094996719,323086777251300 %N A346380 Complement of A187430 in A000108. %C A346380 Related to the decomposition of A000108 as the sum of A055113 and A111160. %F A346380 G.f. y(x) satisfies x y^4 + 2 x^2 y^2 + x^3 + 3 x y^2 + y^3 - x y = 0. %o A346380 (Sage) %o A346380 N = 30 %o A346380 x = (PowerSeriesRing(QQ, 'x').0).O(N + 1) %o A346380 f = (x*(1-x^2)^2/(1+x^3)^2).reverse() %o A346380 g = sum(catalan_number(n)*x**n for n in range(N + 1)).O(N + 1) %o A346380 list(x*g-f) %Y A346380 Cf. A000108, A055113, A111160, A187430. %K A346380 nonn %O A346380 0,5 %A A346380 _F. Chapoton_, Jul 14 2021