A228497 - OEIS

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

(list; constant; graph; refs; listen; history; text; internal format)

OFFSET

0,1

LINKS

Table of n, a(n) for n=0..94.

FORMULA

One divided by A010767.

Square root of A010503.

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

EXAMPLE

0.841068670567930255...

MAPLE

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

MATHEMATICA

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

PROG

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

CROSSREFS

Cf. A010503, A010767.

Sequence in context: A103613 A104768 A199430 * A199285 A049255 A028577

Adjacent sequences: A228494 A228495 A228496 * A228498 A228499 A228500

KEYWORD

cons,nonn

AUTHOR

R. J. Mathar, Aug 23 2013

STATUS

approved