OFFSET
0,7
COMMENTS
The g.f. of column k of array A063260(n,k) (sextinomial coefficients) is (x^(ceiling(k/5)))*N6(k,x)/(1-x)^(k+1).
The sequence of degrees for the polynomials N6(n,x) is [0,0,0,0,0,0,4,5,5,5,5,4,9,10,10,...] for n >= 0.
Row sums N6(n,1)=1 for all n.
FORMULA
a(n, m) = [x^m]N6(n, x), n, m >= 0, with N6(n, x)= sum(((1-x)^(j-1))*(x^(b(c(n), j)))*N6(n-j, x), j=1..5), N6(n, x)= 1 for n=0, 1, 2, 3, 4 and b(c(n), j) := 1 if 1<= j <= c(n) else 0, with c(n) := 4 if mod(n, 5)=0 else c(n) := mod(n, 5)-1; (hence b(0, j)=0, j=1..5).
EXAMPLE
{1}; {1}; {1}; {1}; {1}; {1}; {5, -10, 10, -5, 1}; {4, -5, 0, 5, -4, 1}; ...
c=2: b(2,1)=b(2,2)=1, b(2,j)=0 for j=3,4,5.
N6(7,x)=4-5*x+0*x^2+5*x^3-4*x^4+x^5.
CROSSREFS
KEYWORD
sign,easy,tabf
AUTHOR
Wolfdieter Lang, Jul 24 2001
STATUS
approved