A181644 Eigentriangle for the Catalan triangle (c(x), xc(x)), A033184.

1, 1, 1, 2, 1, 1, 6, 3, 1, 1, 22, 11, 4, 1, 1, 92, 46, 17, 5, 1, 1, 426, 213, 79, 24, 6, 1, 1, 2150, 1075, 399, 122, 32, 7, 1, 1, 11708, 5854, 2173, 665, 176, 41, 8, 1, 1, 68282, 34141, 12673, 3878, 1027, 242, 51, 9, 1, 1, 423948, 211974, 78683, 24075, 6373, 1502

Offset

0,4

Comments

First column is essentially A091768. Inverse of A181645.

Links

Table of n, a(n) for n=0..60.

Paul Barry, Invariant number triangles, eigentriangles and Somos-4 sequences, arXiv preprint arXiv:1107.5490 [math.CO], 2011.

Example

Triangle begins
  1,
  1, 1,
  2, 1, 1,
  6, 3, 1, 1,
  22, 11, 4, 1, 1,
  92, 46, 17, 5, 1, 1,
  426, 213, 79, 24, 6, 1, 1,
  2150, 1075, 399, 122, 32, 7, 1, 1,
  11708, 5854, 2173, 665, 176, 41, 8, 1, 1

Crossrefs

Cf. A033184, A091768, A181645.

Sequence in context: A349933 A120258 A201922 * A144351 A213936 A142589

Adjacent sequences: A181641 A181642 A181643 * A181645 A181646 A181647

Keyword

easy,nonn,tabl

Author

Paul Barry, Nov 03 2010

Status

approved