A099238 Square array read by antidiagonals with rows generated by 1/(1-x-x^(k+1)).
1, 1, 2, 1, 1, 4, 1, 1, 2, 8, 1, 1, 1, 3, 16, 1, 1, 1, 2, 5, 32, 1, 1, 1, 1, 3, 8, 64, 1, 1, 1, 1, 2, 4, 13, 128, 1, 1, 1, 1, 1, 3, 6, 21, 256, 1, 1, 1, 1, 1, 2, 4, 9, 34, 512, 1, 1, 1, 1, 1, 1, 3, 5, 13, 55, 1024, 1, 1, 1, 1, 1, 1, 2, 4, 7, 19, 89, 2048
Offset: 0
Examples
Rows begin 1, 2, 4, 8, 16, 32, 64, 128, 256, ... (A000079) 1, 1, 2, 3, 5, 8, 13, 21, 34, ... (A000045) 1, 1, 1, 2, 3, 4, 6, 9, 13, ... (A000930) 1, 1, 1, 1, 2, 3, 4, 5, 7, ... (A003269) 1, 1, 1, 1, 1, 2, 3, 4, 5, ... (A003520)
Formula
Square array T(n, k) = Sum_{j=0..floor(n/(k+1))} binomial(n-k*j, j), n, k>=0.
Comments