Hexagonal pyramidal numbers, or greengrocer's numbers.

Terms

a(0) =0a(1) =1a(2) =7a(3) =22a(4) =50a(5) =95a(6) =161a(7) =252a(8) =372a(9) =525a(10) =715a(11) =946a(12) =1222a(13) =1547a(14) =1925a(15) =2360a(16) =2856a(17) =3417a(18) =4047a(19) =4750a(20) =5530a(21) =6391a(22) =7337a(23) =8372a(24) =9500a(25) =10725a(26) =12051a(27) =13482a(28) =15022a(29) =16675