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A224470 Numbers n such that 7^n - n is prime. 4
2, 6, 8, 12, 44, 48, 512, 1088, 1104, 6038 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(11) > 92000. - Giovanni Resta, Apr 08 2013

a(11) > 2*10^5. - Robert Price, Feb 11 2014

LINKS

Table of n, a(n) for n=1..10.

MAPLE

A224470:=proc(q) local n;

for n from 1 to q do if isprime(7^n-n) then print(n); fi; od; end:

A224470(10^4); # Paolo P. Lava, Apr 18 2013

PROG

(PARI) forstep(n=2, 10^4, 2, if(ispseudoprime(7^n-n), print1(n, ", "))); /* Joerg Arndt, Apr 07 2013 */

CROSSREFS

Cf. A048744, A058037, A057908, A058046, A058829, A224468.

Sequence in context: A065392 A030457 A296300 * A168247 A229056 A186703

Adjacent sequences:  A224467 A224468 A224469 * A224471 A224472 A224473

KEYWORD

nonn,more

AUTHOR

Alex Ratushnyak, Apr 06 2013

STATUS

approved

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Last modified September 20 03:28 EDT 2020. Contains 337264 sequences. (Running on oeis4.)