

A078027


Expansion of (1x)/(1x^2x^3).


12



1, 1, 1, 0, 0, 1, 0, 1, 1, 1, 2, 2, 3, 4, 5, 7, 9, 12, 16, 21, 28, 37, 49, 65, 86, 114, 151, 200, 265, 351, 465, 616, 816, 1081, 1432, 1897, 2513, 3329, 4410, 5842, 7739, 10252, 13581, 17991, 23833, 31572, 41824, 55405, 73396, 97229, 128801, 170625, 226030, 299426
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OFFSET

0,11


LINKS

Table of n, a(n) for n=0..53.
P. Chinn and S. Heubach, Integer Sequences Related to Compositions without 2's, J. Integer Seqs., Vol. 6, 2003.
Index entries for linear recurrences with constant coefficients, signature (0, 1, 1).


FORMULA

a(n) is asymptotic to r^(n2) / (2*r+3) where r = 1.3247179572447..., the real root of x^3 = x + 1 . For n>=4, a(n) = a(n2) + a(n3) .  Philippe Deléham, Jan 13 2004
a(n) = A182097(n)A182097(n1).  R. J. Mathar, Jan 27 2018


PROG

(PARI) Vec((1x)/(1x^2x^3)+O(x^99)) \\ Charles R Greathouse IV, Sep 23 2012


CROSSREFS

The following are basically all variants of the same sequence: A000931, A078027, A096231, A124745, A133034, A134816, A164001, A182097, A228361 and probably A020720. However, each one has its own special features and deserves its own entry.
Sequence in context: A124745 A133034 A000931 * A134816 A228361 A182097
Adjacent sequences: A078024 A078025 A078026 * A078028 A078029 A078030


KEYWORD

sign,easy


AUTHOR

N. J. A. Sloane, Nov 17 2002


STATUS

approved



