a(n) = T(n,m) + T(n,m+1) + ... + T(n,n), m=[ (n+1)/2 ], T given by A026758.

Terms

a(0) =1a(1) =1a(2) =3a(3) =4a(4) =12a(5) =17a(6) =50a(7) =73a(8) =212a(9) =315a(10) =909a(11) =1365a(12) =3931a(13) =5940a(14) =17122a(15) =25960a(16) =75053a(17) =113951a(18) =330917a(19) =502399a(20) =1467067a(21) =2224888a(22) =6537922a(23) =9896852a(24) =29281109a(25) =44218651a(26) =131765882a(27) =198432519a(28) =595663485a(29) =894311205