A176324 Decimal expansion of (15+7*sqrt(5))/6.

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

Offset

1,1

Comments

Continued fraction expansion of (15+7*sqrt(5))/6 is A010720.

Volume of a triangular hebesphenorotunda (Johnson solid J_92) with unit edges. - Paolo Xausa, Aug 02 2025

Links

G. C. Greubel, Table of n, a(n) for n = 1..1000

Wikipedia, Triangular hebesphenorotunda.

Index entries for algebraic numbers, degree 2.

Formula

Minimal polynomial: 9*x^2 - 45*x - 5. - Amiram Eldar, May 03 2026

Example

5.10874597374975464581070261351982227468072141954678...

Maple

evalf( (15+7*sqrt(5))/6, 100); # G. C. Greubel, Dec 05 2019

Mathematica

RealDigits[(15+7Sqrt[5])/6, 10, 120][[1]]  (* Harvey P. Dale, Apr 18 2011 *)

Prog

(PARI) default(realprecision, 100); (15+7*sqrt(5))/6 \\ G. C. Greubel, Dec 05 2019
(Magma) SetDefaultRealField(RealField(100)); (15+7*Sqrt(5))/6; // G. C. Greubel, Dec 05 2019
(SageMath) numerical_approx((15+7*sqrt(5))/6, digits=100) # G. C. Greubel, Dec 05 2019

Crossrefs

Cf. A002163 (decimal expansion of sqrt(5)), A010720 (repeat 5, 9).

Sequence in context: A390494 A198541 A200420 * A081817 A389717 A361550

Adjacent sequences: A176321 A176322 A176323 * A176325 A176326 A176327

Keyword

nonn,cons,easy

Author

Klaus Brockhaus, Apr 15 2010

Status

approved