Highly composite numbers + 1.

Terms

a(0) =2a(1) =3a(2) =5a(3) =7a(4) =13a(5) =25a(6) =37a(7) =49a(8) =61a(9) =121a(10) =181a(11) =241a(12) =361a(13) =721a(14) =841a(15) =1261a(16) =1681a(17) =2521a(18) =5041a(19) =7561a(20) =10081a(21) =15121a(22) =20161a(23) =25201a(24) =27721a(25) =45361a(26) =50401a(27) =55441a(28) =83161a(29) =110881