A138580 Numbers n such that 2^(2*n-13)-13 is prime.

7, 8, 9, 11, 13, 15, 35, 59, 75

Offset

1,1

Links

Table of n, a(n) for n=1..9.

Example

2^(2*11-13)-13=499, 2^(2*13-13)-13=8179, 2^(2*15-13)-13=131059, ...

Mathematica

q=13; For[i=q, i<=q, a={}; Do[x=2^(2*n-i)-i; If[PrimeQ[x], AppendTo[a, n]], {n, 10^2}]; Print["2^(2*n-", i, ")-", i, " ", a]; i=i+2]

Prog

(PARI) is(n)=isprime(2^(2*n-13)-13) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Sequence in context: A196040 A196043 A030569 * A192050 A045158 A074328

Adjacent sequences: A138577 A138578 A138579 * A138581 A138582 A138583

Keyword

nonn,easy

Author

Vladimir Joseph Stephan Orlovsky, May 13 2008

Status

approved