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A138580
Numbers n such that 2^(2*n-13)-13 is prime.
0
7, 8, 9, 11, 13, 15, 35, 59, 75
OFFSET
1,1
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
KEYWORD
nonn,easy
AUTHOR
STATUS
approved