A136366 Numbers k such that A024530(k) is prime.

3, 4, 5, 10, 21, 31, 55, 77, 121, 135, 148, 192, 425, 570, 612, 649, 1293, 2326, 3646

Offset

1,1

Links

Table of n, a(n) for n=1..19.

Mathematica

f=0; Do[ p=Prime[n]; f=f + (-1)^(n+1)*1/p; g=Numerator[f] ; If[ PrimeQ[g], Print[ {n, g} ] ], {n, 1, 150} ]

Crossrefs

Cf. A024530 (numerator of Sum_{k=1..n} (-1)^k / prime(k)).

Cf. A136365, A136367, A136368, A136369, A136370, A136371.

Sequence in context: A297661 A342333 A369789 * A123820 A261903 A133320

Adjacent sequences: A136363 A136364 A136365 * A136367 A136368 A136369

Keyword

nonn,more

Author

Alexander Adamchuk, Dec 27 2007

Extensions

a(12)-a(16) from Alexander Adamchuk, Sep 15 2010

a(17)-a(19) from Robert Price, Aug 27 2019

Status

approved