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A245278
Decimal expansion of k3, a Diophantine approximation constant such that the conjectured volume of the "critical parallelepiped" is 2^3*k3 (the 3-D analog of A242671).
0
5, 7, 8, 4, 1, 6, 7, 6, 2, 7, 8, 8, 9, 0, 0, 7, 5, 9, 0, 7, 4, 6, 0, 2, 0, 5, 8, 1, 4, 6, 1, 9, 5, 6, 7, 4, 7, 9, 9, 4, 8, 3, 9, 6, 9, 4, 3, 6, 6, 4, 5, 5, 0, 1, 5, 4, 8, 3, 1, 7, 6, 7, 4, 9, 4, 1, 7, 9, 6, 0, 2, 0, 8, 2, 4, 1, 2, 2, 0, 7, 1, 4, 5, 0, 6, 5, 8, 2, 7, 4, 8, 7, 0, 0, 2, 7, 9, 3, 9, 1
OFFSET
0,1
REFERENCES
Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, Section 2.23 Diophantine approximation constants, p. 176.
FORMULA
8/7*cos(2*Pi/7)*cos(Pi/7)^2.
Also equals the positive root of 343*x^3 - 147*x^2 - 28*x - 1.
EXAMPLE
0.578416762788900759074602058146195674799483969436645501548317674941796...
MATHEMATICA
RealDigits[8/7*Cos[2*Pi/7]*Cos[Pi/7]^2, 10, 100] // First
CROSSREFS
Cf. A242671.
Sequence in context: A233527 A244355 A374771 * A155855 A070366 A339986
KEYWORD
nonn,cons,easy
AUTHOR
STATUS
approved