A115367 Row sums of correlation triangle for Fredholm-Rueppel sequence A036987.

1, 2, 2, 4, 4, 4, 5, 6, 7, 6, 9, 6, 9, 6, 10, 8, 12, 8, 14, 8, 14, 8, 16, 8, 16, 8, 16, 8, 16, 8, 17, 10, 19, 10, 21, 10, 21, 10, 23

Offset: 0

Author

Paul Barry, Jan 21 2006

Keywords

• easy
• nonn

Comments

If a sequence has g.f. A(x), its correlation triangle has g.f. A(x)A(x*y)/(1-x^2*y). (Observation due to Christian G. Bower).

Formula

G.f. : (sum{k>=0, x^(2k-1)})^2/(1-x^2); a(n)=sum{k=0..n, sum{j=0..k, A036987(j)}*sum{j=0..n-k, A036987(j)*(-1)^(n-k-j)}}.