A237193 Decimal expansion of 3^i + 3^(-i), where i = sqrt(-1).

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

Offset

0,1

Comments

Approximately equals 1/log(3) = 0.9102... or 23/(15^(1/2)+4^(2/3))^(1/2) = 0.909664848... .

Links

Table of n, a(n) for n=0..84.

Formula

Equals 2*cos(log(3)). [Bruno Berselli, Feb 05 2014]

Example

0.909664845653219510055130287190084968176380338549139663022520422852...

Mathematica

RealDigits[ Chop[ N[ 3^I + 3^(-I), 111], 10^-110], 10, 111]

Crossrefs

Cf. A237192.

Sequence in context: A160576 A104756 A154994 * A132268 A252851 A241290

Adjacent sequences: A237190 A237191 A237192 * A237194 A237195 A237196

Keyword

nonn,cons,easy

Author

Robert G. Wilson v, Feb 04 2014

Status

approved