Triangle T(n, k) = k^2*(1+n)^2 - 4*n, read by rows.

Terms

a(0) =0a(1) =-4a(2) =0a(3) =-8a(4) =1a(5) =28a(6) =-12a(7) =4a(8) =52a(9) =132a(10) =-16a(11) =9a(12) =84a(13) =209a(14) =384a(15) =-20a(16) =16a(17) =124a(18) =304a(19) =556a(20) =880a(21) =-24a(22) =25a(23) =172a(24) =417a(25) =760a(26) =1201a(27) =1740a(28) =-28a(29) =36