A129882 Sequence i_{t_n} arising in enumeration of arrays of directed blocks (see Quaintance reference for precise definition), where i_n = A129876, t_n = A129875.

0, 2, 4, 4, 12, 18, 56, 72

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: A319594 A065449 A130618 * A129017 A086915 A059927

Adjacent sequences: A129879 A129880 A129881 * A129883 A129884 A129885

Keyword

nonn,more

Author

N. J. A. Sloane, May 26 2007

Status

approved