Lapidary numbers.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =2a(6) =3a(7) =4a(8) =6a(9) =8a(10) =12a(11) =16a(12) =23a(13) =31a(14) =45a(15) =61a(16) =87a(17) =119a(18) =171a(19) =233a(20) =334a(21) =459a(22) =655a(23) =904a(24) =1288a(25) =1782a(26) =2535a(27) =3517a(28) =4995a(29) =6935