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A215633 Decimal expansion of sum(n>=1, 1/n^(n^prime(n)) ) 0
1, 0, 0, 3, 9, 0, 6, 2, 5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET

1,4

COMMENTS

Is this a finite sequence? (or equivalently, is this constant rational?)

Unlikely: the "apparent" rationality seems to be caused by the rapid growth of the denominators; one may instead speculate that the value is transcendental. - Joerg Arndt, Feb 05 2013

The constant is approximately 257/256 (see A021260).

LINKS

Table of n, a(n) for n=1..118.

EXAMPLE

1.00390625000000000000000000... = 1 + 1/2^8 + 1/3^243 + 1/4^16384+...

PROG

(PARI) suminf(n=1, 1/n^(n^prime(n)))

CROSSREFS

Cf. A062481.

Sequence in context: A248726 A267411 A021260 * A134878 A154540 A324834

Adjacent sequences:  A215630 A215631 A215632 * A215634 A215635 A215636

KEYWORD

cons,nonn

AUTHOR

Balarka Sen, Aug 18 2012

STATUS

approved

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Last modified August 8 09:16 EDT 2020. Contains 336293 sequences. (Running on oeis4.)