OFFSET
1,2
LINKS
S. Chaiken, C. R. H. Hanusa and T. Zaslavsky, A q-queens problem I. General theory, preprint, August 7, 2014.
S. Chaiken, C. R. H. Hanusa and T. Zaslavsky, A q-queens problem II. The square board, preprint, August 7, 2014. See Corollary 5.2.
Index entries for linear recurrences with constant coefficients, signature (3,-1,-5,5,1,-3,1).
FORMULA
a(n) = n^4/2 - 5*n^3/24 - 11*n/48 + (-1)^n*n/16.
G.f.: -x^2*(x^4+7*x^3+18*x^2+16*x+6) / ((x-1)^5*(x+1)^2). [Colin Barker, Feb 16 2013]
MATHEMATICA
LinearRecurrence[{3, -1, -5, 5, 1, -3, 1}, {0, 6, 34, 114, 285, 602, 1127}, 50] (* Harvey P. Dale, Mar 09 2016 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Feb 16 2013
STATUS
approved