A046672 Expansion of 1/(1-2*x-3*x^2+2*x^3).

1, 2, 7, 18, 53, 146, 415, 1162, 3277, 9210, 25927, 72930, 205221, 577378, 1624559, 4570810, 12860541, 36184394, 101808791, 286449682, 805956949, 2267645362, 6380262207, 17951546602, 50508589101, 142111293594, 399845261287, 1125007225154

Offset

0,2

Links

Iain Fox, Table of n, a(n) for n = 0..2226

Richard M. Low and Ardak Kapbasov, Non-Attacking Bishop and King Positions on Regular and Cylindrical Chessboards, Journal of Integer Sequences, Vol. 20 (2017), Article 17.6.1, Table 6.

Index entries for linear recurrences with constant coefficients, signature (2, 3, -2).

Formula

a(n) = 2*a(n-1) + 3*a(n-2) - 2*a(n-3), n > 2. - Iain Fox, Dec 02 2017

Prog

(PARI) first(n) = Vec(1/(1-2*x-3*x^2+2*x^3) + O(x^n)) \\ Iain Fox, Dec 02 2017

Crossrefs

Partial sums of A054854.

Cf. A101197.

Sequence in context: A006869 A099626 A261331 * A046866 A291255 A294004

Adjacent sequences: A046669 A046670 A046671 * A046673 A046674 A046675

Keyword

nonn,easy

Author

N. J. A. Sloane, Nov 17 2002

Status

approved