login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A061015 Numerator of Sum_{i=1..n} 1/p(i)^2, p(i) = i-th prime. 5
1, 13, 361, 18589, 2293369, 392915461, 114454369129, 41578647715669, 22089188627685001, 18626778064527922741, 17942190650501641587001, 24603083510737933160021269, 41412850736015889039729489289 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

FORMULA

a(1) = 1; a(n) = a(n-1)*p(n)^2+(p(1)*...*p(n-1))^2. - Zak Seidov (zakseidov(AT)yahoo.com), Sep 28 2002

MAPLE

summ := 0: for n from 1 to 100 do if (isprime(n)) then summ := summ + 1/n^2; printf("%d, ", numer(summ)); #printf("%d, ", denom(summ)); end if; od; evalf(summ);

CROSSREFS

Cf. A075986, A075987.

Sequence in context: A160396 A078738 A165391 * A183472 A009040 A009085

Adjacent sequences:  A061012 A061013 A061014 * A061016 A061017 A061018

KEYWORD

easy,nonn,frac

AUTHOR

Winston C. Yang (winston(AT)cs.wisc.edu), May 21 2001

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 17 02:08 EST 2012. Contains 205978 sequences.