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%I #10 Jul 09 2018 04:00:29
%S 1,2,1,9,7,2,0,8,5,9,0,4,0,3,1,1,8,4,4,1,6,9,6,0,6,7,6,0,4,1,4,6,7,7,
%T 9,4,4,3,9,0,4,1,5,5,0,5,5,4,1,5,6,9,6,7,8,2,8,7,9,7,4,4,1,7,8,7,3,3,
%U 8,4,6,4,5,9,9,0,8,3,9,0,6,5,8,3,5,5,3,9,3,2,0,7,8,5,1,6,2,5,9,5,7,8
%N Decimal expansion of the sixth smallest known Salem number.
%H M. J. Mossinghoff, <a href="http://www.cecm.sfu.ca/~mjm/Lehmer/lists/SalemList.html">Small Salem Numbers</a>
%H Eric Weisstein's MathWorld, <a href="http://mathworld.wolfram.com/SalemConstants.html">Salem Constants.</a>
%H Wikipedia, <a href="http://en.wikipedia.org/wiki/Salem_number">Salem number</a>
%F Equals root of p = 1 - x - x^8 + x^9 - x^10 - x^17 + x^18 with largest absolute value.
%e 1.219720859040311844169606760414677944390415505541569678287974417873...
%t c1 = {1, -1, 0, 0, 0, 0, 0, 0, -1, 1};
%t c2 = Join[c1, Reverse[Most[c1]]];
%t p = (x^Range[0, Length[c2] - 1]).c2;
%t sigma6 = Root[p, x, 2];
%t RealDigits[sigma6, 10, 102][[1]]
%Y Cf. A073011 (sigma1), A219300 (sigma2), A306078 (sigma3 ), A306079 (sigma4), A316605 (sigma5), A316607 (sigma7), A316608 (sigma8), A316609 (sigma9), A316610 (sigma10).
%K nonn,cons
%O 1,2
%A _Jean-François Alcover_, Jul 08 2018