Right edge of the triangle A045975.

Terms

a(0) =1a(1) =4a(2) =21a(3) =36a(4) =85a(5) =120a(6) =217a(7) =280a(8) =441a(9) =540a(10) =781a(11) =924a(12) =1261a(13) =1456a(14) =1905a(15) =2160a(16) =2737a(17) =3060a(18) =3781a(19) =4180a(20) =5061a(21) =5544a(22) =6601a(23) =7176a(24) =8425a(25) =9100a(26) =10557a(27) =11340a(28) =13021a(29) =13920