A228497 Decimal expansion of the fourth root of 1/2.

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

Offset: 0

Author

R. J. Mathar, Aug 23 2013

Keywords

• cons
• nonn

Comments

Height of a equilateral square antiprism of edge length 1. - R. J. Mathar, Mar 06 2025

Examples

			0.8408964152537145430311254762...
		

Links

• E. W. Weisstein, Antiprism, MathWorld
• Index entries for algebraic numbers, degree 4.

Crossrefs

Cf. A010503, A010767.

Programs

Maple

evalf(1/root[4](2)) ;

Mathematica

RealDigits[Surd[1/2,4],10,120][[1]] (* Harvey P. Dale, Oct 05 2014 *)

PARI

sqrtn(2,-4) \\ Charles R Greathouse IV, Apr 15 2014

Formula

One divided by A010767.

Square root of A010503.

Equals Product_{k>=1} (1 + (-1)^k/(4*k+1)). - Amiram Eldar, Aug 10 2020