A246965 Numbers n such that 19*n-(n+19) is a prime.

2, 4, 5, 6, 7, 11, 12, 14, 15, 16, 21, 25, 26, 27, 29, 30, 32, 34, 37, 39, 40, 41, 44, 46, 47, 49, 50, 54, 55, 60, 62, 65, 67, 69, 71, 72, 77, 81, 84, 85, 89, 90, 91, 92, 96, 105, 106, 107, 111, 112, 116, 117, 120, 124, 127, 131, 132, 134, 135, 137, 145, 146

Offset

1,1

Links

Jens Kruse Andersen, Table of n, a(n) for n = 1..10000

Formula

a(n) = A138918(n)+1.

Example

17 = (19*2)-(19+2) is prime, so 2 is a term.

Mathematica

Select[Range[150], PrimeQ[18#-19]&] (* Harvey P. Dale, Jun 10 2016 *)

Prog

(PHP)
for($num=1; $num<x; $num++)
{
    $num2=$i;
    $finalnumber=($num2*19)-($num2+19);
    //gmp_nextprime will find a primenumber greater than the given number
    $prime=gmp_nextprime($finalnumber-1);
    if($prime==$finalnumber)
    {
         $sequence=$sequence.", ".$prime;
    }
}
echo $sequence;
(PARI) lista(nn) = {for (n=1, nn, if (isprime(18*n-19), print1(n, ", ")); ); } \\ Michel Marcus, Sep 09 2014
(Sage) [n for n in (2..200) if is_prime(18*n-19)] # Bruno Berselli, Sep 09 2014

Crossrefs

Sequence in context: A318606 A057461 A070116 * A300861 A039057 A317185

Adjacent sequences: A246962 A246963 A246964 * A246966 A246967 A246968

Keyword

nonn

Author

Shanmuga Subramanian, Sep 08 2014

Status

approved