A055911 - OEIS

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A055911

Column 5 of triangle A055907.

1, 10, 56, 240, 854, 2654, 7412, 18974, 45173, 101074, 214361, 433731, 841921, 1574765, 2849215, 5002411, 8546675, 14243335, 23202995, 37016099, 57925111, 89043169, 134635403, 200468817, 294253144, 426179565, 609587498, 861767228

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OFFSET

5,2

COMMENTS

The given generating function does not appear to generate the sequence. - Sean A. Irvine, Apr 09 2022

LINKS

Table of n, a(n) for n=5..32.

A. J. Guttmann and A. R. Conway, Hexagonal lattice directed site animals, Statistical Physics on the Eve of the Twenty-First Century, ed. M. T. Batchelor, World Scientific, 1999 (H_5 for hexagonal lattices Table 1).

FORMULA

G.f.: x^5*(1 + 4x + 8x^2 + 22x^3 + 37x^4 + 56x^5 + 88x^6 + 98x^7 + 137x^8 + 118x^9 + 145x^10 + 113x^11 + 104x^12 + 79x^13 + 50x^14 + 40x^15 + 17x^16 + 10x^17 + 6x^18 + x^20) / ((1 - x)^11 * (1 + x)^5 * (1 + x^2)^4 * (1 + x^2 + x^4)^2).

CROSSREFS

Cf. A055907.

Sequence in context: A053309 A035040 A002889 * A087076 A014483 A116971

Adjacent sequences: A055908 A055909 A055910 * A055912 A055913 A055914

KEYWORD

nonn

AUTHOR

Christian G. Bower, Jun 15 2000

STATUS

approved