A138582 Numbers n such that 2^(2*n-19)-19 is prime.

10, 11, 12, 13, 15, 17, 19, 20, 25, 29, 43, 44, 52, 88, 95, 105, 137, 155, 199

Offset

1,1

Links

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

Example

2^(2*15-19)-19=2029, 2^(2*17-19)-19=32749, ...

Mathematica

q=19; 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-19)-19) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Sequence in context: A270040 A339093 A072554 * A215059 A362264 A308105

Adjacent sequences: A138579 A138580 A138581 * A138583 A138584 A138585

Keyword

nonn,easy

Author

Vladimir Joseph Stephan Orlovsky, May 13 2008

Status

approved