171281

Appears in sequences

• Number of solutions to c(1)*prime(2)+...+c(n)*prime(n+1) = 1, where c(i) = +-1 for i > 1, c(1) = 1.at n=26A022898
• Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected in a 3X2 elbow 1,1 1,2 1,3 2,3 in any orientation.at n=8A145950