Self-convolution of array T given by A026626.

Terms

a(0) =1a(1) =2a(2) =11a(3) =34a(4) =138a(5) =492a(6) =1830a(7) =6804a(8) =25576a(9) =96728a(10) =367932a(11) =1405884a(12) =5392590a(13) =20751504a(14) =80076872a(15) =309748096a(16) =1200669828a(17) =4662772672a(18) =18137643524a(19) =70657441212a(20) =275620281310