Coefficient of x in the reduction by x^2->x+3 of the polynomial p(n,x)=1+x^n+x^(2n).

A192469

Coefficient of x in the reduction by x^2->x+3 of the polynomial p(n,x)=1+x^n+x^(2n).

Terms

    a(0) =2a(1) =8a(2) =44a(3) =224a(4) =1178a(5) =6200a(6) =32786a(7) =173600a(8) =919988a(9) =4877072a(10) =25858754a(11) =137115440a(12) =727074530a(13) =3855471416a(14) =20444603516a(15) =108412922240a(16) =574888887530

External references