-2991

Appears in sequences

• a(n+3) = 2a(n+2) - 3a(n+1) + 2a(n); a(0) = 1, a(1) = -1, a(2) = -2.at n=23A105225
• Row sums of A129392.at n=10A129393
• a(0) = 1; a(n) = -Sum_{k=0..floor((n-1)/2)} binomial(n-1,2*k) * a(k) * a(n-2*k-1).at n=10A351941