A059877 Those n for which the absolute value of A059876[n] is prime.

1, 3, 4, 5, 6, 10, 11, 12, 13, 15, 16, 17, 18, 21, 22, 24, 26, 27, 28, 30, 32, 33, 34, 38, 39, 40, 41, 42, 45, 46, 48, 50, 51, 52, 54, 55, 56, 57, 59, 60, 63, 64, 67, 68, 69, 70, 72, 74, 75, 76, 78, 79, 80, 81, 83, 84, 85, 87, 89, 93, 94, 96, 98, 102, 103, 104, 105, 109, 111

Offset: 1

Author

Antti Karttunen, Feb 05 2001

Keywords

• nonn

Comments

Of the first 511 terms of A059876, 278 are primes.

Crossrefs

Cf. A059879.

Programs

Maple

positions(true,map(isprime,map(abs, A059876))); # positions function given in A059649.

Mathematica

a[n_] := With[{s = Floor[Log[2, n]]}, (-1)^(n+1) + Sum[(-1)^(Floor[n/2^i] + 1)*Prime[i], {i, 1, s}] + If[1 == n, 1, Mod[s + 1, 2]*Prime[s]]];
A059877 = Position[Array[a, 120], p_ /; PrimeQ[Abs[p]]] // Flatten (* Jean-François Alcover, Mar 07 2016 *)