a(n) = self-convolution of row n of array T given by A027960.

Terms

a(0) =1a(1) =11a(2) =42a(3) =145a(4) =473a(5) =1484a(6) =4529a(7) =13543a(8) =39870a(9) =115937a(10) =333781a(11) =953056a(12) =2702497a(13) =7618115a(14) =21365778a(15) =59657329a(16) =165926609a(17) =459905588a(18) =1270819025a(19) =3501855007a(20) =9625627686a(21) =26398369601a(22) =72248624077a(23) =197361589960a(24) =538199264833