578017

Appears in sequences

• G.f. satisfies A(x) = 1 + x*A(x)*A(x^2)*A(x^3)*...*A(x^n)*...at n=22A091865
• Number of (n+1) X 5 0..2 matrices with each 2 X 2 subblock idempotent.at n=20A224672