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

Offset: 5

Author

Christian G. Bower, Jun 15 2000

Keywords

• nonn

Comments

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

Links

• 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).

Crossrefs

Cf. A055907.

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).