A055899 Column 3 of triangle A055898.

1, 7, 31, 101, 272, 636, 1340, 2600, 4725, 8135, 13391, 21217, 32536, 48496, 70512, 100296, 139905, 191775, 258775, 344245, 452056, 586652, 753116, 957216, 1205477, 1505231, 1864695, 2293025, 2800400, 3398080, 4098496, 4915312

Offset: 3

Author

Christian G. Bower, Jun 13 2000

Keywords

• nonn
• easy

Links

• A. J. Guttmann, Indicators of solvability for lattice models, Discrete Math., 217 (2000), 167-189 (H_3 for square lattices of Section 6).

Crossrefs

Cf. A055898 (triangle), A055900 (column 4), A055901 (5), A055902 (6), A055903 (7), A055904 (8).

Programs

Mathematica

CoefficientList[Series[(1+2*x+4*x^2+2*x^3+x^4)/((1-x)^7*(1+x)^2), {x, 0, 40}], x] (* Georg Fischer, Aug 16 2021 *)

Formula

G.f.: x^3(1+2x+4x^2+2x^3+x^4)/((1-x)^7(1+x)^2). [Corrected by Georg Fischer, Aug 16 2021]