Similar to A072921 but starting with 2.

Terms

a(0) =2a(1) =4a(2) =10a(3) =17a(4) =32a(5) =52a(6) =79a(7) =122a(8) =170a(9) =226a(10) =292a(11) =371a(12) =461a(13) =562a(14) =676a(15) =809a(16) =959a(17) =1132a(18) =1312a(19) =1499a(20) =1709a(21) =1936a(22) =2182a(23) =2441a(24) =2711a(25) =2992a(26) =3295a(27) =3617a(28) =3956a(29) =4318