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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. 1
2, 2, 6, 6, 22, 24, 90, 100 (list; graph; refs; listen; history; text; internal format)
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

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Last modified June 21 10:09 EDT 2021. Contains 345360 sequences. (Running on oeis4.)