Number of partitions of n into distinct summands (A000009), plus 1 (apart from the first term).

Terms

a(0) =1a(1) =2a(2) =2a(3) =3a(4) =3a(5) =4a(6) =5a(7) =6a(8) =7a(9) =9a(10) =11a(11) =13a(12) =16a(13) =19a(14) =23a(15) =28a(16) =33a(17) =39a(18) =47a(19) =55a(20) =65a(21) =77a(22) =90a(23) =105a(24) =123a(25) =143a(26) =166a(27) =193a(28) =223a(29) =257