Number of terms with n digits in A154780.

Terms

a(0) =1a(1) =1a(2) =2a(3) =2a(4) =4a(5) =6a(6) =12a(7) =17a(8) =34a(9) =55a(10) =98a(11) =161a(12) =288a(13) =448a(14) =811a(15) =1265a(16) =2145a(17) =3425a(18) =5860a(19) =9305a(20) =15384a(21) =24690a(22) =40445a(23) =64715