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A253634 Decimal expansion of Sum_{n>=1} 1/A033286(n)^2. 0
2, 8, 4, 1, 7, 0, 7, 0, 5, 4, 7, 0, 8, 6, 8, 2, 5, 0, 1, 7, 7, 1, 4 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

The convergence is very slow, need to use the first 100000000 primes to obtain the correct value of the coefficient of 10^(-23).

The constant is in the interval [0.28417070547086825017714, 0.28417070547086825017743]; these safe limits are computed by accumulating in parallel the partial sum of the lower estimate 1/n^4 = Zeta(4). - R. J. Mathar, Feb 06 2015

The next digits after ...17714 appear to be 3618. - Jon E. Schoenfield, Jan 05 2019

LINKS

Table of n, a(n) for n=0..22.

EXAMPLE

0.284170705470...

PROG

(PFGW & SCRIPT)

SCRIPT

DIM i, 0

DIM j, 0

DIM n

DIM m

DIMS t

OPENFILEOUT myf, a(n).txt

OPENFILEIN maf, pre.txt

LABEL loop1

SET i, i+1

IF i>10000000 THEN END

GETNEXT n, maf

SET j, j+10^10000/((i*n)^2)

IF i%1000000==0 THEN SET m, j/10^9970

IF i%1000000==0 THEN WRITE myf, m

GOTO loop1

CROSSREFS

Cf. A033286 (n*prime(n)), A124012.

Sequence in context: A264818 A264709 A200004 * A152626 A093823 A088154

Adjacent sequences:  A253631 A253632 A253633 * A253635 A253636 A253637

KEYWORD

nonn,cons,more

AUTHOR

Pierre CAMI, Jan 07 2015

STATUS

approved

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Last modified September 21 08:38 EDT 2020. Contains 337268 sequences. (Running on oeis4.)