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A136371
Numbers k such that A136370(k) is prime.
6
1, 2, 3, 5, 46, 227, 232, 336, 360, 3919
OFFSET
1,2
MATHEMATICA
f=1; Do[ p=Prime[n]; f=f - (-1)^(n+1)*1/p^2; g=Numerator[f] ; If[ PrimeQ[g], Print[ {n, g} ] ], {n, 1, 100} ]
PROG
(Python) # uses A136370gen() and imports from A136370
from sympy import isprime
def agen(): yield from (k for k, ak in enumerate(A136370gen(), 1) if isprime(ak))
print(list(islice(agen(), 5))) # Michael S. Branicky, Jun 26 2022
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. A136370: numerator of 1 - Sum_{k=1..n} (-1)^(k+1)/prime(k)^2.
Sequence in context: A117460 A281252 A208223 * A060380 A062608 A041791
KEYWORD
nonn,more
AUTHOR
Alexander Adamchuk, Dec 27 2007
EXTENSIONS
More terms added and edited by Alexander Adamchuk, Sep 15 2010
a(10) from Robert Price, Aug 29 2019
STATUS
approved