T(n,0) + T(n,1) + ... + T(n,n), T given by A026692.

Terms

a(0) =1a(1) =2a(2) =4a(3) =8a(4) =18a(5) =42a(6) =92a(7) =194a(8) =430a(9) =982a(10) =2158a(11) =4608a(12) =10198a(13) =23116a(14) =50840a(15) =109178a(16) =241472a(17) =545148a(18) =1199474a(19) =2584664a(20) =5714476a(21) =12867300a(22) =28319264a(23) =61166388a(24) =135200076a(25) =303859934a(26) =668886256a(27) =1447227562a(28) =3198315058a(29) =7177895844