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%I #10 Dec 01 2014 20:22:19
%S 1,1,246,19003476,16875655269948,90784545100668913392,
%T 2041012695880532470281654960,150277870737901828652705825755721760,
%U 30495546426686489361833408314854897254404320,14997592385781765578538605874290442908069285068834560
%N Number of distinct n-colored necklaces with 7 beads per color.
%H Alois P. Heinz, <a href="/A208188/b208188.txt">Table of n, a(n) for n = 0..35</a>
%F a(n) = Sum_{d|7} phi(7/d)*(n*d)!/(d!^n*n*7) if n>0 and a(0) = 1.
%e a(0) = 1: the empty necklace.
%e a(1) = 1: {0000000}.
%e a(2) = 246: {00000001111111, ..., 01010101010101}.
%p with(numtheory);
%p a:= n-> `if`(n=0, 1, add(phi(7/d) *(n*d)!/(d!^n *7*n), d={1, 7})):
%p seq(a(n), n=0..12);
%Y Row n=7 of A208183.
%Y Cf. A000010, A000142.
%K nonn
%O 0,3
%A _Alois P. Heinz_, Feb 24 2012