a(n) = 1*T(n,0) + 2*T(n,1) + ... + (2n+1)*T(n,2n), T given by A027926.

Terms

a(0) =1a(1) =6a(2) =22a(3) =66a(4) =178a(5) =450a(6) =1090a(7) =2562a(8) =5890a(9) =13314a(10) =29698a(11) =65538a(12) =143362a(13) =311298a(14) =671746a(15) =1441794a(16) =3080194a(17) =6553602a(18) =13893634a(19) =29360130a(20) =61865986a(21) =130023426a(22) =272629762a(23) =570425346a(24) =1191182338a(25) =2483027970a(26) =5167382530a(27) =10737418242