Main diagonal of array A[k,n] = n-th sum of k consecutive k-gonal numbers, k>2.

Terms

a(0) =4a(1) =30a(2) =125a(3) =365a(4) =854a(5) =1724a(6) =3135a(7) =5275a(8) =8360a(9) =12634a(10) =18369a(11) =25865a(12) =35450a(13) =47480a(14) =62339a(15) =80439a(16) =102220a(17) =128150a(18) =158725a(19) =194469a(20) =235934a(21) =283700a(22) =338375a(23) =400595a(24) =471024a(25) =550354a(26) =639305a(27) =738625a(28) =849090a(29) =971504