Self-convolution of array T given by A026386.

Terms

a(0) =1a(1) =2a(2) =6a(3) =34a(4) =116a(5) =678a(6) =2438a(7) =14494a(8) =53538a(9) =321590a(10) =1207186a(11) =7301142a(12) =27702096a(13) =168359754a(14) =643682106a(15) =3926147730a(16) =15096518580a(17) =92338836390a(18) =356629256930