Self-convolution of array T given by A026659.

Terms

a(0) =1a(1) =2a(2) =6a(3) =34a(4) =116a(5) =438a(6) =1606a(7) =8732a(8) =32194a(9) =136010a(10) =514118a(11) =2728662a(12) =10331502a(13) =45631466a(14) =174779986a(15) =918698714a(16) =3522338416a(17) =15916323366a(18) =61429039906a(19) =321217490812