OFFSET
0,2
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..5598
EXAMPLE
a(0) = 1: (0).
a(1) = 4: (0,1), (0,1,0), (1,0), (1).
...
a(4) = 13: (0,1,0,1,0,1,0,1), (0,1,0,1,0,1,0,1,0), (1,0,1,0,1,0,1,0), (1,0,1,0,1,0,1), (0,1,0,1,2), (1,0,1,2), (2,1,0,1,0), (2,1,0,1), (0,1,2,1,0), (0,1,2,1), (1,2,1,0), (1,2,1), (4).
PROG
(PARI)
M(k) = matrix(k+1, k+1, i, j, if(i==j, 1, if(i==j-1, -x^(i-1), if(i==j+1, -x^(i-1), 0))))
A_x(N) = {my(k=N+1, x='x+O('x^k)); Vec(vecsum(M(k)^(-1) * vector(k+1, i, x^(i-1))~))}
A_x(10)
CROSSREFS
KEYWORD
nonn
AUTHOR
John Tyler Rascoe, May 02 2025
STATUS
approved
