OFFSET
1,2
COMMENTS
A wazir is a (fairy chess) leaper [0,1].
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
R. J. Mathar, Bivariate generating functions for non-attacking wazirs on rectangular boards, viXra:2404.0122 (2024) Section 3.
Eric Weisstein's World of Mathematics, Grid Graph
Wikipedia, Wazir (chess)
FORMULA
a(n) = (3*n - 5)*(3*n^2 - 8*n + 8)/2, n>=2.
G.f.: x^2*(3*x^3+8*x^2+14*x+2)/(x-1)^4. - Vaclav Kotesovec, Mar 25 2010
MATHEMATICA
CoefficientList[Series[x (3 x^3 + 8 x^2 + 14 x + 2) / (x - 1)^4, {x, 0, 50}], x] (* Vincenzo Librandi, May 28 2013 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vaclav Kotesovec, Jan 29 2010
STATUS
approved