Number of increasing subsequences that can be made from the sequence of successive numbers.

Terms

a(0) =1a(1) =2a(2) =3a(3) =5a(4) =7a(5) =11a(6) =15a(7) =22a(8) =30a(9) =51a(10) =75a(11) =119a(12) =196a(13) =309a(14) =472a(15) =698a(16) =1018a(17) =1498a(18) =2130a(19) =3005a(20) =4262a(21) =5909a(22) =7884a(23) =10579a(24) =14543a(25) =19884a(26) =27182a(27) =36278a(28) =48440a(29) =63730