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A084248 Decimal expansion of c = Product_{k>=1} (1 + 1/t(k)) where t(k) = k(k+1)/2 is the k-th triangular number. 2
5, 0, 7, 9, 2, 2, 0, 2, 0, 8, 6, 6, 3, 6, 7, 8, 3, 3, 6, 0, 4, 3, 6, 8, 7, 9, 5, 6, 7, 8, 2, 0, 2, 1, 0, 7, 4, 8, 3, 2, 3, 9, 7, 3, 4, 5, 7, 0, 8, 3, 5, 9, 7, 7, 4, 2, 8, 4, 8, 2, 4, 3, 7, 9, 1, 6, 8, 7, 4, 5, 9, 0, 9, 3, 2, 9, 1, 9, 9, 0, 6, 9, 4, 7, 0, 1, 5, 4, 5, 4, 9, 0, 2, 3, 3, 4, 9, 0, 3, 6, 1, 0, 2, 8, 8 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET

1,1

REFERENCES

Bruce C. Berndt, Ramanujan Notebook part II, Infinite series, Springer Verlag, p. 241.

LINKS

Table of n, a(n) for n=1..105.

FORMULA

Equals ((1/2)/Pi)*cosh(Pi/2*sqrt(7)).

EXAMPLE

5.07922020866367833604368795...

PROG

(PARI) 1/2/Pi*cosh(Pi/2*sqrt(7))

CROSSREFS

Sequence in context: A114124 A155827 A244045 * A201417 A147666 A343071

Adjacent sequences:  A084245 A084246 A084247 * A084249 A084250 A084251

KEYWORD

cons,nonn

AUTHOR

Benoit Cloitre, Jun 21 2003

STATUS

approved

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Last modified December 1 22:12 EST 2021. Contains 349435 sequences. (Running on oeis4.)