Principal diagonal of the convolution array A213771.

Terms

a(0) =1a(1) =11a(2) =42a(3) =106a(4) =215a(5) =381a(6) =616a(7) =932a(8) =1341a(9) =1855a(10) =2486a(11) =3246a(12) =4147a(13) =5201a(14) =6420a(15) =7816a(16) =9401a(17) =11187a(18) =13186a(19) =15410a(20) =17871a(21) =20581a(22) =23552a(23) =26796a(24) =30325a(25) =34151a(26) =38286a(27) =42742a(28) =47531a(29) =52665