Number of strings of n numbers x(i) in -2..2 with sums of x(i) and of x(i)*x(i+1) both zero.

A183937

Number of strings of n numbers x(i) in -2..2 with sums of x(i) and of x(i)*x(i+1) both zero.

Terms

    a(0) =1a(1) =1a(2) =5a(3) =15a(4) =81a(5) =237a(6) =1015a(7) =3891a(8) =16171a(9) =66237a(10) =297003a(11) =1304467a(12) =5981617a(13) =27407859a(14) =126441771a(15) =584452845a(16) =2721978059a(17) =12719931479a(18) =59862174023a(19) =282898499059

External references