Central nonzero values of A231599.

Terms

a(0) =1a(1) =2a(2) =2a(3) =4a(4) =6a(5) =8a(6) =16a(7) =28a(8) =50a(9) =100a(10) =196a(11) =388a(12) =786a(13) =1600a(14) =3280a(15) =6780a(16) =14060a(17) =29280a(18) =61232a(19) =128414a(20) =270084a(21) =569514a(22) =1203564a(23) =2548770a(24) =5407754a(25) =11493312a(26) =24465960a(27) =52157508a(28) =111342192a(29) =237985596