OFFSET
1,8
COMMENTS
An amazon (superqueen) moves like a queen and a knight.
LINKS
FORMULA
G.f.: 4*x^8*(x^9+x^8+7*x^7-6*x^6+5*x^5+10*x^4+x^3+6*x^2+4*x+1)/(x-1)^6.
Explicit formula: a(n) = n^5-44n^4+823n^3-8168n^2+42796n -93984, n>=12.
MATHEMATICA
CoefficientList[Series[4 x^7 (x^9 + x^8 + 7 x^7 - 6 x^6 + 5 x^5 + 10 x^4 + x^3 + 6 x^2 + 4 x + 1) / (x - 1)^6, {x, 0, 50}], x] (* Vincenzo Librandi, May 30 2013 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vaclav Kotesovec, Mar 25 2010
EXTENSIONS
More terms from Vincenzo Librandi, May 30 2013
STATUS
approved