Rhombic dodecahedral numbers: a(n) = n^4 - (n - 1)^4.

Terms

a(0) =1a(1) =15a(2) =65a(3) =175a(4) =369a(5) =671a(6) =1105a(7) =1695a(8) =2465a(9) =3439a(10) =4641a(11) =6095a(12) =7825a(13) =9855a(14) =12209a(15) =14911a(16) =17985a(17) =21455a(18) =25345a(19) =29679a(20) =34481a(21) =39775a(22) =45585a(23) =51935a(24) =58849a(25) =66351a(26) =74465a(27) =83215a(28) =92625a(29) =102719