A046653 Triangle of rooted planar maps.

1, 1, 1, 1, 1, 2, 1, 2, 3, 4, 1, 2, 8, 12, 14, 1, 3, 12, 30, 43, 49, 1, 3, 22, 63, 134, 189, 216, 1, 4, 31, 133, 323, 608, 888, 984, 1, 4, 48, 238, 759, 1671, 2988, 4332, 4862, 1, 5, 64, 422, 1594, 4260, 8772, 15126, 22011, 24739, 1, 5, 90, 694, 3210, 10002, 23986, 46923, 79214, 115131, 130338, 1, 6, 115, 1106, 6024, 22176, 60813, 135097, 255277, 424034, 616395, 701584

Offset

2,6

Links

Table of n, a(n) for n=2..79.

W. G. Brown, Enumeration of non-separable planar maps, Canad. J. Math., 15 (1963), 526-545.

W. G. Brown, Enumeration of non-separable planar maps [Annotated scanned copy]

Formula

Reference gives generating functions.

Example

Triangle begins:
  1;
  1,  1;
  1,  1,  2;
  1,  2,  3,  4;
  1,  2,  8, 12, 14;
  1,  3, 12, 30, 43, 49;
  ...

Maple

# uses function L(., .) from A046650
for n from 2 to 13 do
for m from n to 2 by -1 do
    printf("%d, ", L(n, m)) ;
end do:
printf("\n") ;
end do: # R. J. Mathar, Apr 13 2019

Crossrefs

Cf. A046650 (diagonal), A000087 (row sums).

Sequence in context: A309776 A255560 A328472 * A308897 A353293 A162190

Adjacent sequences: A046650 A046651 A046652 * A046654 A046655 A046656

Keyword

tabl,nonn,easy

Author

N. J. A. Sloane

Extensions

More terms from R. J. Mathar, Apr 13 2019

Status

approved