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A152149 Decimal expansion of the angle B in the triangle ABC that is both side-golden and angle-golden. +0
1
6, 5, 7, 4, 0, 5, 4, 8, 2, 9, 7, 6, 5, 3, 2, 5, 9, 2, 3, 8, 0, 9, 6, 8, 5, 4, 1, 5, 2, 9, 3, 9, 7, 1, 2, 6, 5, 4, 1, 4, 9, 5, 9, 4, 6, 4, 8, 7, 8, 3, 9, 3, 7, 0, 7, 8, 2, 0, 9, 2, 8, 0, 8, 5, 8, 8, 5, 3, 9, 5, 0, 6, 1, 3, 8, 1, 7, 7, 3, 5, 0, 7, 0, 1, 7, 1, 5, 1, 6, 5, 4, 4, 0, 5, 2, 2, 7, 8, 0, 5, 2, 8, 1, 2, 6 (list; cons; graph; listen)
OFFSET

0,1

COMMENT

There is a unique (shape of) triangle ABC that is both side-golden and

angle-golden. Its angles are B, t*B and pi-B-t*B, where t is the golden

ratio. "Angle-golden" and "side-golden" refer to partitionings of ABC,

each in a manner that matches the continued fraction [1,1,1,...] of t.

REFERENCES

Clark Kimberling, Two kinds of golden triangles, generalized to match continued fractions," Journal for Geometry and Graphics, 11 (2007) 165-171.

Clark Kimberling, "A new kind of golden triangle," in Applications of Fibonacci Numbers, Proc. Fourth International Conference on Fibonacci Numbers and Their Applications, Kluwer, 1991.

Jordi Dou, Clark Kimberling and Laurence Kuipers, "A Fibonacci sequence of nested triangles," Problem S29, Amer. Math. Monthly 89 (1982) 696-697; proposed 87 (1980) 302.

FORMULA

B is the number in [0,pi] such that sin(B*t^2)=t*sin(B),

where t=(1+5^(1/2))/2, the golden ratio.

EXAMPLE

The number B begins with 0.65740548 (equivalent to 37.666559... degrees)

CROSSREFS

Cf. A000045.

Sequence in context: A101634 A071176 A089826 this_sequence A086268 A021156 A063046

Adjacent sequences: A152146 A152147 A152148 this_sequence A152150 A152151 A152152

KEYWORD

nonn,cons

AUTHOR

Clark Kimberling (ck6(AT)evansville.edu), Nov 26 2008

EXTENSIONS

Keyword:cons added and offset corrected by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jun 18 2009

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Last modified December 21 10:15 EST 2009. Contains 171081 sequences.


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