a(n) = 2^n * [x^n] Product_{k>=1} 1/(1 - 2*x^k)^(1/2).

Terms

a(0) =1a(1) =2a(2) =10a(3) =36a(4) =150a(5) =524a(6) =2116a(7) =7528a(8) =29158a(9) =107404a(10) =409388a(11) =1526712a(12) =5843580a(13) =22048056a(14) =84476488a(15) =322465104a(16) =1240657798a(17) =4769404556a(18) =18436257820a(19) =71280387736a(20) =276583603220