Main diagonal of array in A083140.

Terms

a(0) =2a(1) =9a(2) =35a(3) =91a(4) =209a(5) =377a(6) =629a(7) =817a(8) =1219a(9) =1769a(10) =2201a(11) =2923a(12) =3649a(13) =4343a(14) =5029a(15) =5989a(16) =7729a(17) =8479a(18) =10117a(19) =11573a(20) =12629a(21) =14299a(22) =16019a(23) =17711a(24) =21631a(25) =23129a(26) =24617a(27) =26857a(28) =28667a(29) =30623