# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a346735 Showing 1-1 of 1 %I A346735 #6 Jul 31 2021 09:44:05 %S A346735 1,1,1,1,1,1,3,6,10,15,21,34,63,120,220,381,642,1102,1968,3615,6658, %T A346735 12090,21675,38820,70200,128466,236583,435453,798798,1462933,2684352, %U A346735 4945740,9145839,16942356,31388571,58140726,107753364,199993359,371852269,692375844,1290252474 %N A346735 G.f. A(x) satisfies: A(x) = 1 + x + x^2 + x^3 + x^4 + x^5 * A(x)^3. %F A346735 a(0) = ... = a(4) = 1; a(n) = Sum_{i=0..n-5} Sum_{j=0..n-i-5} a(i) * a(j) * a(n-i-j-5). %t A346735 nmax = 40; A[_] = 0; Do[A[x_] = 1 + x + x^2 + x^3 + x^4 + x^5 A[x]^3 + O[x]^(nmax + 1) // Normal, nmax + 1]; CoefficientList[A[x], x] %t A346735 a[n_] := a[n] = If[n < 5, 1, Sum[Sum[a[i] a[j] a[n - i - j - 5], {j, 0, n - i - 5}], {i, 0, n - 5}]]; Table[a[n], {n, 0, 40}] %Y A346735 Cf. A001764, A019497, A307972, A346733, A346734. %K A346735 nonn %O A346735 0,7 %A A346735 _Ilya Gutkovskiy_, Jul 30 2021 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE