A316609 Decimal expansion of the ninth smallest known Salem number.

1, 2, 3, 5, 6, 6, 4, 5, 8, 0, 3, 8, 9, 7, 4, 7, 3, 0, 8, 1, 0, 5, 1, 6, 9, 3, 5, 1, 5, 3, 1, 2, 6, 3, 4, 7, 9, 7, 2, 3, 5, 1, 0, 0, 4, 2, 7, 4, 6, 2, 3, 9, 0, 7, 7, 6, 5, 0, 4, 3, 8, 0, 7, 7, 2, 0, 6, 3, 1, 1, 9, 2, 4, 9, 4, 0, 2, 7, 8, 1, 4, 9, 8, 8, 9, 1, 6, 6, 0, 7, 4, 0, 4, 2, 6, 3, 8, 5, 9, 2, 5

Offset

1,2

Links

Table of n, a(n) for n=1..101.

M. J. Mossinghoff, Small Salem Numbers

Eric Weisstein's MathWorld, Salem Constants.

Wikipedia, Salem number

Formula

p = 1 - x^2 - x^3 + x^7 + x^8 - x^10 - x^11 - x^12 + x^14 + x^15 - x^19 - x^20 + x^22.

Example

1.2356645803897473081051693515312634797235100427462390776504380772063...

Mathematica

c1 = {1, 0, -1, -1, 0, 0, 0, 1, 1, 0, -1, -1};
c2 = Join[c1, Reverse[Most[c1]]];
p = (x^Range[0, Length[c2] - 1]).c2;
sigma9 = Root[p, x, 2];
RealDigits[sigma9, 10, 101][[1]]

Crossrefs

Cf. A073011 (sigma1), A219300 (sigma2), A306078 (sigma3 ), A306079 (sigma4), A316605 (sigma5), A316606 (sigma6), A316607 (sigma7), A316608 (sigma8), A316610 (sigma10).

Sequence in context: A001600 A175578 A347861 * A307327 A000036 A165081

Adjacent sequences: A316606 A316607 A316608 * A316610 A316611 A316612

Keyword

nonn,cons

Author

Jean-François Alcover, Jul 08 2018

Status

approved