A207528 Decimal expansion of 4th du Bois-Reymond constant.

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

Offset: 0

Author

Alonso del Arte, Feb 24 2012

Keywords

• nonn
• cons

Examples

			0.0052407046777047711...
		

References

• Steven R. Finch, Mathematical Constants, Cambridge, 2003, pp. 237-239.

Links

• Eric Weisstein's World of Mathematics, du Bois-Reymond Constants.

Crossrefs

Cf. A138730 (continued fraction expansion).

Cf. A062546 (c2), A224196 (c3), A243108 (c5), A245333 (c6).

Programs

Mathematica

RealDigits[(E^4 - 4E^2 - 25)/8, 10, 100][[1]]

Formula

2*Sum_{k>=1} (1 + (x_k)^2)^(-2) = (e^4 - 4*e^2 - 25)/8, where x_k is the k-th root of t = tan t and e = 2.71828... is the natural logarithm base.