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 A346076 a(n) = 1 + Sum_{k=1..n-4} a(k) * a(n-k-4). 2
 1, 1, 1, 1, 1, 2, 3, 4, 5, 7, 11, 17, 25, 36, 54, 84, 131, 201, 307, 475, 745, 1172, 1837, 2878, 4531, 7173, 11381, 18057, 28669, 45624, 72796, 116336, 186066, 297865, 477505, 766621, 1232214, 1982292, 3191693, 5143974, 8298640, 13399691, 21652705, 35014373, 56663700 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,6 LINKS FORMULA G.f. A(x) satisfies: A(x) = 1 / (1 - x) + x^4 * A(x) * (A(x) - 1). MATHEMATICA a[n_] := a[n] = 1 + Sum[a[k] a[n - k - 4], {k, 1, n - 4}]; Table[a[n], {n, 0, 44}] nmax = 44; A[_] = 0; Do[A[x_] = 1/(1 - x) + x^4 A[x] (A[x] - 1) + O[x]^(nmax + 1) // Normal, nmax + 1]; CoefficientList[A[x], x] CROSSREFS Cf. A105633, A217282, A307971, A343305, A346048, A346073, A346075, A346077. Sequence in context: A245823 A143284 A343305 * A339357 A279065 A327325 Adjacent sequences:  A346073 A346074 A346075 * A346077 A346078 A346079 KEYWORD nonn AUTHOR Ilya Gutkovskiy, Jul 04 2021 STATUS approved

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Last modified December 2 11:44 EST 2021. Contains 349440 sequences. (Running on oeis4.)