260496

Appears in sequences

• a(n) = a(n-1) + a(n-2) + 1 for n>1, a(0)=0, a(1)=4.at n=24A022309
• G.f. A(x) satisfies: 1 = Sum_{n>=0} (-x/2)^n * (A(x)^n + (-1)^n)^n.at n=7A360949