OFFSET
1,1
COMMENTS
Vertical cylinder: a chessboard where it is supposed that the columns 1 and 20 are in contact (number of columns = 20, number of rows = 2n).
LINKS
V. Kotesovec, Non-attacking chess pieces
Index entries for linear recurrences with constant coefficients, signature (13, -76, 264, -606, 966, -1092, 876, -489, 181, -40, 4).
FORMULA
Recurrence: a(n) = 4*a(n-11) - 40*a(n-10) + 181*a(n-9) - 489*a(n-8) + 876*a(n-7) - 1092*a(n-6) + 966*a(n-5) - 606*a(n-4) + 264*a(n-3) - 76*a(n-2) + 13*a(n-1).
G.f.: -(1 + 2035*x + 121804*x^2 + 1302988*x^3 + 3919832*x^4 + 3822444*x^5 + 1204400*x^6 + 113216*x^7 + 3167*x^8 + 13*x^9)/((x-1)^9*(2*x-1)^2).
a(n) = (296191755*n - 3519976573)*2^n + 524495/2016*n^8 + 4217363/504*n^7 + 2363921/16*n^6 + 66422455/36*n^5 + 557314865/32*n^4 + 8943856601/72*n^3 + 322704776641/504*n^2 + 90034143925/42*n + 3519976574.
CROSSREFS
KEYWORD
nonn
AUTHOR
Vaclav Kotesovec, Sep 22 2011
STATUS
approved