Floor-Sqrt transform of numbers of A004148 (secondary structures).

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =2a(6) =4a(7) =6a(8) =9a(9) =13a(10) =20a(11) =31a(12) =47a(13) =73a(14) =112a(15) =174a(16) =269a(17) =418a(18) =651a(19) =1015a(20) =1586a(21) =2481a(22) =3886a(23) =6095a(24) =9571a(25) =15048a(26) =23684a(27) =37312a(28) =58837a(29) =92857