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A282468 Decimal expansion of the zeta function at 2 of every second prime number. 0
1, 4, 4, 7, 1, 5, 5, 8, 6, 6, 8, 8 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..11.

FORMULA

Equals Sum_{n>=1} 1/A031215(n)^2 = Sum_{n>=1} 1/A000040(2n)^2.

EXAMPLE

1/3^2 + 1/7^2 + 1/13^2 + 1/19^2 + 1/29^2 + ... = 0.144715586688...

PROG

(PARI)

sum(n=1, 2500000, 1./prime(2*n)^2)

CROSSREFS

Cf. A002808, A031215.

Zeta functions at 2:  A085548 (for primes), A275647 (for nonprimes), A013661 (for natural numbers), A117543 (for semiprimes), A131653 (for triprimes), A222171 (for even numbers), A111003 (for odd numbers).

Sequence in context: A090531 A198138 A240924 * A196463 A021695 A131844

Adjacent sequences:  A282465 A282466 A282467 * A282469 A282470 A282471

KEYWORD

nonn,cons,hard,more

AUTHOR

Terry D. Grant, Apr 14 2017

EXTENSIONS

Four more digits from Jon E. Schoenfield, Jan 21 2018

STATUS

approved

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Last modified February 19 07:39 EST 2018. Contains 299330 sequences. (Running on oeis4.)