A246725 Decimal expansion of r_3, the third smallest radius for which a compact packing of the plane exists, with disks of radius 1 and r_3.

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

Offset: 0

Author

Jean-François Alcover, Sep 02 2014

Keywords

• nonn
• cons
• easy

Comments

Essentially the same digit sequence as A188934 and A188485. - R. J. Mathar, Sep 06 2014

Examples

			0.2807764064044151374553524639935192562867998063434051...
		

Links

• Steven R. Finch, Errata and Addenda to Mathematical Constants, p. 62.
• Index entries for algebraic numbers, degree 2.

Crossrefs

Cf. A246723 (r_1), A246724 (r_2), A246726 (r_4), A246727 (r_5), A002193 (r_6 = sqrt(2)-1), A246728 (r_7), A246729 (r_8), A246730 (r_9).

Programs

Mathematica

RealDigits[(Sqrt[17] - 3)/4, 10, 103] // First

PARI

(sqrt(17)-3)/4 \\ Charles R Greathouse IV, Feb 10 2025

Formula

(sqrt(17) - 3)/4.