A356470 Decimal expansion of (3 - sqrt(5))/(2*sqrt(2)).

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

Offset

0,1

Comments

Distance between points in the most spread-out hexagonal lattice such that the gap formed by any three mutually tangential unit disks contains a point inside or on its boundary.

Side-length of an equilateral triangle contained in a unit side-length equilateral triangle such that every vertex and midpoint of the smaller triangle is at distance 1/2 from the nearest vertex of the larger triangle.

A quartic number with denominator 2. Minimal polynomial is 4x^4 - 14x^2 + 1. - Charles R Greathouse IV, Sep 29 2022

Links

Table of n, a(n) for n=0..88.

Andrew Slattery, Interactive

Index entries for algebraic numbers, degree 4

Example

0.2700907567377264536...

Mathematica

First[RealDigits[N[(3-Sqrt[5])/(2Sqrt[2]), 89]]] (* Stefano Spezia, Aug 08 2022 *)

Prog

(PARI) (3-sqrt(5))/sqrt(8) \\ Charles R Greathouse IV, Sep 29 2022

Crossrefs

Cf. A002193.

Sequence in context: A100378 A020819 A111953 * A260929 A290789 A199292

Adjacent sequences: A356467 A356468 A356469 * A356471 A356472 A356473

Keyword

nonn,cons

Author

Andrew Slattery, Aug 08 2022

Extensions

More terms from Stefano Spezia, Aug 08 2022

Status

approved