A247553 Decimal expansion of A(rectangles), an analog of Moser's worm constant, which is associated with the class of rectangular regions of the plane.

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

Offset

0,1

References

Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, Section 8.4 Moser's Worm Constant, p. 492.

Links

Table of n, a(n) for n=0..101.

Formula

A = beta*sqrt(1 - beta^2), where beta is A240969.

Example

0.39438476883681362825403921854319968160795399...

Mathematica

phi = ArcSin[1/6 + (4/3)*Sin[(1/3)*ArcSin[17/64]]]; psi = ArcTan[(1/2)*Sec[phi]]; beta = (1/2)*(Pi/2 - phi - 2*psi + Tan[phi] + Tan[psi])^(-1); A = beta*Sqrt[1 - beta^2]; RealDigits[A, 10, 102] // First

Crossrefs

Cf. A240969 (beta).

Sequence in context: A154368 A321120 A243711 * A307238 A161773 A212992

Adjacent sequences: A247550 A247551 A247552 * A247554 A247555 A247556

Keyword

nonn,cons

Author

Jean-François Alcover, Sep 19 2014

Status

approved