A136369 Numbers k such that A136368(k) is prime.

2, 5, 6, 8, 18, 20, 98, 1863

Offset

1,1

Links

Table of n, a(n) for n=1..8.

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_{k=1..n} (-1)^(k+1)/prime(k)^2).

Cf. A136365, A136366, A136367, A136370, A136371.

Sequence in context: A271430 A326854 A097685 * A305511 A269472 A351830

Adjacent sequences: A136366 A136367 A136368 * A136370 A136371 A136372

Keyword

nonn,more

Author

Alexander Adamchuk, Dec 27 2007

Extensions

a(8) from Robert Price, Aug 28 2019

Status

approved