A246322 Triangle read by rows: T(n,k) = number of neutral planar lambda terms of size n with k free variables (n >= 0, 1 <= k <= n+1).
1, 1, 1, 3, 4, 2, 14, 20, 15, 5, 83, 120, 105, 56, 14, 570, 820, 770, 504, 210, 42, 4318, 6152, 5985, 4368, 2310, 792, 132, 35068, 49448, 49014, 38136, 23100, 10296, 3003, 429
Offset: 0
Examples
Triangle begins: 1 1,1 3,4,2 14,20,15,5 83,120,105,56,14, 570,820,770,504,210,42 4318,6152,5985,4368,2310,792,132 35068,49448,49014,38136,23100,10296,3003,429 ...
Links
- Noam Zeilberger and Alain Giorgetti, A correspondence between rooted planar maps and normal planar lambda terms, arXiv:1408.5028 [cs.LO], 2014.