OFFSET
0,2
FORMULA
a(n)=T(n,0)+T(n-1,1)+...+T(0,n), where T is formulated at A065775.
Empirical g.f.: 2*x*(x^13-x^9-3*x^7-x^6-4*x^2-3*x-3) / ((x-1)^3*(x+1)*(x^2+1)*(x^2+x+1)^2). - Colin Barker, May 04 2014
EXAMPLE
For n=3, the least number of knight's moves to the points (i.e., squares) (3,0), (2,1), (1,2), (0,3) are 3,1,1,3, respectively, for a total of a(3)=8.
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Dec 20 2010
STATUS
approved