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A047918 Triangular array a(n,k) = Sum_{d|k} mu(d)*U(n,k/d) if k|n else 0, where U(n,k)=A047916(n,k) (1<=k<=n). 5
1, 2, 0, 6, 0, 0, 8, 0, 0, 16, 20, 0, 0, 0, 100, 12, 24, 36, 0, 0, 648, 42, 0, 0, 0, 0, 0, 4998, 32, 32, 0, 320, 0, 0, 0, 39936, 54, 0, 270, 0, 0, 0, 0, 0, 362556, 40, 160, 0, 0, 3800, 0, 0, 0, 0, 3624800, 110, 0, 0, 0, 0, 0, 0, 0, 0, 0, 39916690, 48, 96 (list; table; graph; refs; listen; history; internal format)
OFFSET

0,2

REFERENCES

J. E. A. Steggall, On the numbers of patterns which can be derived from certain elements, Mess. Math., 37 (1907), 56-61.

CROSSREFS

Sequence in context: A153059 A151336 A180491 * A138701 A050821 A076257

Adjacent sequences:  A047915 A047916 A047917 * A047919 A047920 A047921

KEYWORD

nonn,tabl,nice,easy

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

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Last modified February 16 21:04 EST 2012. Contains 205969 sequences.