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A137915 Decimal expansion of 180*arccos(1/3)/Pi. 1
7, 0, 5, 2, 8, 7, 7, 9, 3, 6, 5, 5, 0, 9, 3, 0, 8, 6, 3, 0, 7, 5, 4, 0, 0, 0, 6, 6, 0, 0, 3, 7, 5, 6, 4, 0, 3, 6, 9, 9, 3, 1, 5, 6, 8, 9, 9, 0, 9, 2, 0, 5, 1, 7, 1, 1, 8, 2, 8, 8, 9, 3, 6, 4, 3, 9, 6, 0, 2, 5, 3, 5, 6, 1, 9, 3, 9, 6, 0, 4, 4, 3, 6, 6, 3, 8, 1, 2, 8, 7, 1, 1, 6, 3, 9, 4, 1, 2, 3, 5, 4, 3, 1, 4, 8 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET

2,1

COMMENTS

Dihedral angle in degrees of regular tetrahedron.

Polar angle (or apex angle) of the cone that subtends exactly one third of the full solid angle. - Stanislav Sykora, Feb 20 2014

LINKS

Table of n, a(n) for n=2..106.

Jackson, Frank and Weisstein, Eric W., Tetrahedron

Weisstein, Eric W., Dihedral Angle

FORMULA

180*A137914/Pi = 180*arccos(1/3)/Pi.

EXAMPLE

70.52877936550930863075400066003756403699315689909205171182889364396025356...

MATHEMATICA

RealDigits[180 ArcCos[1/3]/Pi, 10, 120][[1]] (* Harvey P. Dale, Jul 13 2013 *)

PROG

(PARI) 180*acos(1/3)/Pi

CROSSREFS

Cf. A137914 (same in radians).

Sequence in context: A033150 A064648 A116198 * A272037 A198114 A193012

Adjacent sequences:  A137912 A137913 A137914 * A137916 A137917 A137918

KEYWORD

cons,nonn

AUTHOR

Rick L. Shepherd, Feb 22 2008

STATUS

approved

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Last modified May 24 18:18 EDT 2017. Contains 286997 sequences.