Central coefficient in (1 + x + 2^n*x^2)^n.

A188140

Central coefficient in (1 + x + 2^n*x^2)^n.

Terms

    a(0) =1a(1) =1a(2) =9a(3) =49a(4) =1729a(5) =31361a(6) =5613441a(7) =297047297a(8) =310070491137

External references