%I M3127 #17 Mar 22 2018 09:48:13
%S 3,31,171,1575,8403,77206,411771,3828187,20176803,185374380,988663371,
%T 9083344725,48444505203,445083891551,2373780754971,22068742956375
%N Number of free subsets of multiplicative group of GF(7^n).
%C 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
%D 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.
%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%Y Cf. A007232.
%K nonn
%O 1,1
%A _Simon Plouffe_