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

0,4

Links

Table of n, a(n) for n=0..35.

Noam Zeilberger and Alain Giorgetti, A correspondence between rooted planar maps and normal planar lambda terms, arXiv:1408.5028 [cs.LO], 2014.

Example

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
  ...

Crossrefs

Cf. A000108, A001791, A220910, A246323.

Sequence in context: A072565 A159672 A059114 * A166074 A225475 A259334

Adjacent sequences: A246319 A246320 A246321 * A246323 A246324 A246325

Keyword

nonn,tabl,more

Author

N. J. A. Sloane, Aug 28 2014

Status

approved