A075079 Numbers k in A001597 such that 2*k + 1 is prime.

1, 8, 9, 36, 81, 125, 128, 216, 243, 441, 576, 729, 900, 1089, 1296, 1331, 1728, 1764, 2025, 4356, 5184, 5625, 7569, 8000, 8649, 9216, 9261, 9801, 10404, 11025, 15129, 17424, 17576, 18225, 19683, 23409, 24336, 24389, 26244, 27000, 31329, 32768, 34596, 35721

Offset

1,2

Links

Table of n, a(n) for n=1..44.

Example

2*8 + 1 = 17 is prime, so 8 is a term.

Prog

(PARI) lista(nn) = {vec = vector(nn, i, i); pp = select(i->((ispower(i) || (i==1)) && isprime(2*i+1)), vec); for (i = 1, #pp, print1(pp[i], ", ")); } \\ Michel Marcus, Oct 02 2013

Crossrefs

Cf. A001597, A075081.

Sequence in context: A036764 A129548 A322797 * A317379 A376120 A298665

Adjacent sequences: A075076 A075077 A075078 * A075080 A075081 A075082

Keyword

easy,nonn

Author

Zak Seidov, Oct 11 2002

Extensions

More terms from Michel Marcus, Oct 02 2013

Status

approved