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A261054
Expansion of ( 2+x-x^2+x^3 ) / (1-x^2-x)^3 .
1
2, 7, 20, 51, 118, 260, 548, 1121, 2236, 4373, 8412, 15960, 29926, 55547, 102196, 186567, 338258, 609532, 1092328, 1947829, 3457724, 6112873, 10766328, 18896880, 33062090, 57675631, 100338836, 174117915, 301432558, 520686644, 897559340, 1544207369, 2651881468, 4546263293, 7781245524
OFFSET
0,1
COMMENTS
Third column of A234713.
FORMULA
a(n) = 2*A001628(n) +A001628(n-1) -A001628(n-2) +A001628(n-3).
MATHEMATICA
LinearRecurrence[{3, 0, -5, 0, 3, 1}, {2, 7, 20, 51, 118, 260}, 40] (* Harvey P. Dale, Aug 10 2024 *)
CROSSREFS
Cf. A234713.
Sequence in context: A123203 A309298 A335927 * A134311 A362973 A066373
KEYWORD
nonn,easy
AUTHOR
R. J. Mathar, Aug 08 2015
STATUS
approved