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A207528 Decimal expansion of 4th Du Bois Reymond constant. 7
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 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET

0,3

REFERENCES

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

LINKS

Table of n, a(n) for n=0..96.

Eric W. Weisstein, MathWorld: Du Bois Reymond Constants.

FORMULA

2 sum(k = 1..infinity) (1 + (x_k)^2)^(-2) = (e^4 - 4e^2 - 25)/8, where x_k is the k-th root of t = tan t and e is the natural logarithm base (approx. 2.71828).

EXAMPLE

0.0052407046777047711...

MATHEMATICA

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

CROSSREFS

Cf. A138730 (continued fraction expansion).

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

Sequence in context: A277581 A307381 A256167 * A019901 A187059 A267120

Adjacent sequences:  A207525 A207526 A207527 * A207529 A207530 A207531

KEYWORD

nonn,cons

AUTHOR

Alonso del Arte, Feb 24 2012

STATUS

approved

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Last modified June 4 07:43 EDT 2020. Contains 334822 sequences. (Running on oeis4.)