Number of closed lambda-terms of size n with at most 2 free de Bruijn indices.
A220896
Number of closed lambda-terms of size n with at most 2 free de Bruijn indices.
Terms
- a(0) =2a(1) =7a(2) =41a(3) =312a(4) =2784a(5) =27917a(6) =307943a(7) =3690055a(8) =47635777a(9) =658405747a(10) =9695617821a(11) =151488900012
External references
- oeis: A220896