A129881 Sequence i_{s_n} arising in enumeration of arrays of directed blocks (see Quaintance reference for precise definition), where i_n = A129876, s_n = A129873.

2, 2, 6, 6, 22, 24, 90, 100

Offset

1,1

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: A128057 A128014 A135401 * A132369 A282169 A081123

Adjacent sequences: A129878 A129879 A129880 * A129882 A129883 A129884

Keyword

nonn,more

Author

N. J. A. Sloane, May 26 2007

Status

approved