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A007233 Number of free subsets of multiplicative group of GF(7^n).
(Formerly M3127)
1
3, 31, 171, 1575, 8403, 77206, 411771, 3828187, 20176803, 185374380, 988663371, 9083344725, 48444505203, 445083891551, 2373780754971, 22068742956375 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Observe that a(2*n+1) = (7^(2*n+1) - 1)/2 for n = 0,1,2,...,7. Does this result hold for general n? - Peter Bala, Mar 22 2018

REFERENCES

P. Bouchard and Y.-N. Yeh, Finding f-free subsets of maximal cardinality, Séries Formelles et Combinatoire Algébrique, 4th colloquium, 15-19 Juin 1992, Montréal, Université du Québec à Montréal, pp. 11-17.

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

LINKS

Table of n, a(n) for n=1..16.

CROSSREFS

Cf. A007232.

Sequence in context: A089286 A089287 A125085 * A197892 A198009 A060416

Adjacent sequences:  A007230 A007231 A007232 * A007234 A007235 A007236

KEYWORD

nonn

AUTHOR

Simon Plouffe

STATUS

approved

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Last modified January 17 17:12 EST 2019. Contains 319235 sequences. (Running on oeis4.)