A129878 Sequence a_n arising in enumeration of arrays of directed blocks (see Quaintance reference for precise definition).

1, 3, 10, 42, 178, 787, 3552, 16319

Offset

1,2

References

Jocelyn Quaintance, Combinatoric Enumeration of Two-Dimensional Proper Arrays, Discrete Math., 307 (2007), 1844-1864.

Links

Table of n, a(n) for n=1..8.

Formula

See Quaintance reference for generating functions that produce A129872-A129886.

Crossrefs

Sequence in context: A370537 A214835 A149059 * A094558 A074511 A000249

Adjacent sequences: A129875 A129876 A129877 * A129879 A129880 A129881

Keyword

nonn,more

Author

N. J. A. Sloane, May 26 2007

Status

approved