Main diagonal of A332374.

Terms

a(0) =3a(1) =15a(2) =53a(3) =127a(4) =285a(5) =511a(6) =901a(7) =1447a(8) =2249a(9) =3231a(10) =4637a(11) =6367a(12) =8713a(13) =11439a(14) =14801a(15) =18739a(16) =23733a(17) =29339a(18) =36269a(19) =44131a(20) =53305a(21) =63347a(22) =75329a(23) =88587a(24) =103973a(25) =120607a(26) =139505a(27) =160151a(28) =183925a(29) =209387