A129877 Sequence i_{a_n} arising in enumeration of arrays of directed blocks (see Quaintance reference for precise definition), where i_n is A129876, a_n is A129878.

2, 0, 6, 12, 58, 220, 958, 4184

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: A357367 A110667 A347929 * A371913 A307581 A261566

Adjacent sequences: A129874 A129875 A129876 * A129878 A129879 A129880

Keyword

nonn,more

Author

N. J. A. Sloane, May 26 2007

Status

approved