A293557 Decimal expansion of real root of x^7 - x^6 - x^5 + x^2 - 1.

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

Offset: 1

Author

Iain Fox, Oct 11 2017

Keywords

• cons
• nonn

Comments

This root is also the seventh smallest of the Pisot numbers.

Examples

			1.545215649732755243252550...
		

Links

• Iain Fox, Table of n, a(n) for n = 1..20000
• Eric Weisstein's World of Mathematics, Pisot Number.
• Wikipedia, Pisot-Vijayaraghavan number
• Index entries for algebraic numbers, degree 7.

Crossrefs

Cf. A060006, A086106, A228777, A092526, A293508, A293509, A374002, A293506, A374003.

Programs

Mathematica

First[RealDigits[Root[#^7 - #^6 - #^5 + #^2 - 1 &, 1], 10, 100]] (* Paolo Xausa, Jun 25 2024 *)

PARI

solve(x=1, 2, x^7 - x^6 - x^5 + x^2 - 1) \\ Michel Marcus, Oct 13 2017

PARI

{ default(realprecision, 20080); x=solve(x=1, 2, x^7 - x^6 - x^5 + x^2 - 1); for (n=1, 20000, d=floor(x); x=(x-d)*10; write("b293557.txt", n, " ", d)); }