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

 

Logo

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A136369 Numbers n such that A136368(n) is prime. 6
2, 5, 6, 8, 18, 20, 98 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..7.

MATHEMATICA

f=0; Do[ p=Prime[n]; f=f + (-1)^(n+1)*1/p^2; g=Numerator[f] ; If[ PrimeQ[g], Print[ {n, g} ] ], {n, 1, 100} ]

CROSSREFS

Cf. A024530 = Numerator of Sum_{k=1..n} (-1)^k / prime(k). Cf. A136368 = Numerator of Sum[ (-1)^(k+1)*1/Prime[k]^2, {k, 1, n} ] ]. Cf. A136365, A136366, A136367, A136370, A136371.

Sequence in context: A191140 A271430 A097685 * A305511 A269472 A244272

Adjacent sequences:  A136366 A136367 A136368 * A136370 A136371 A136372

KEYWORD

more,nonn

AUTHOR

Alexander Adamchuk, Dec 27 2007

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified January 20 16:46 EST 2019. Contains 319335 sequences. (Running on oeis4.)