265286

Appears in sequences

• Triangle read by rows: T(n,k), n >=1, 0 <= k <= C(n,k), = number of n X n symmetric positive definite matrices with 2's on the main diagonal and 1's and 0's elsewhere and with k 1's above the diagonal.at n=69A080858
• G.f. A(x) satisfies A(x) = 1 + Sum_{n>=1} A(x)^n * 2*x^n/(1 - 2*x^(2*n)).at n=9A192403