a(n) = Pell(n)*A008655(n) for n>=1, with a(0)=1, where A008655 lists the coefficients in (theta_3(x)*theta_3(3*x)+theta_2(x)*theta_2(3*x))^4.

A209448

a(n) = Pell(n)*A008655(n) for n>=1, with a(0)=1, where A008655 lists the coefficients in (theta_3(x)*theta_3(3*x)+theta_2(x)*theta_2(3*x))^4.

Terms

    a(0) =1a(1) =24a(2) =432a(3) =4440a(4) =21024a(5) =87696a(6) =559440a(7) =1395264a(8) =5728320a(9) =23852760a(10) =64719648a(11) =183528288a(12) =898460640a(13) =1765134672a(14) =6002425728a(15) =21820957200a(16) =52895150208a(17) =134056553904a(18) =598084104240

External references