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A157292 Decimal expansion of 315/(2*Pi^4). 1
1, 6, 1, 6, 8, 9, 2, 2, 0, 5, 1, 1, 2, 7, 8, 2, 7, 9, 2, 2, 9, 1, 5, 6, 3, 3, 6, 4, 5, 7, 1, 1, 9, 4, 3, 2, 7, 3, 3, 7, 8, 7, 8, 7, 9, 1, 9, 4, 8, 0, 2, 6, 3, 7, 8, 1, 1, 1, 4, 6, 5, 5, 8, 6, 8, 3, 5, 8, 5, 1, 8, 7, 1, 3, 9, 9, 4, 2, 7, 4, 3, 9, 2, 2, 8, 9, 0, 0, 1, 5, 3, 9, 0, 0, 8, 2, 5, 2, 2, 6, 3, 6, 2, 7, 2 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

The product_{p= primes} (1 + 1/p^2 + 1/p^4).

Whereas, the product over (1 + 2/p^2 + 1/p^4) equals A082020^2.

LINKS

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

FORMULA

Equals A013661/A013664 = product_{i>=1} (1+1/A001248(i)+1/A030514(i)).

Equals 315*A092744/2.

Equals Sum_{n>=1} 1/A004709(n)^2. - Geoffrey Critzer, Feb 16 2015

EXAMPLE

1.61689220511... = (1+1/2^2+1/2^4)*(1+1/3^2+1/3^4)*(1+1/5^2+1/5^4)*(1+1/7^2+1/7^4)*...

MAPLE

evalf(315/2/Pi^4) ;

MATHEMATICA

RealDigits[N[Zeta[2]/Zeta[6], 150]][[1]] (* Geoffrey Critzer, Feb 16 2015 *)

CROSSREFS

Sequence in context: A011300 A222068 A272055 * A159828 A131114 A199230

Adjacent sequences:  A157289 A157290 A157291 * A157293 A157294 A157295

KEYWORD

cons,easy,nonn

AUTHOR

R. J. Mathar, Feb 26 2009

STATUS

approved

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Last modified April 17 05:12 EDT 2021. Contains 343059 sequences. (Running on oeis4.)