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A273601 Numbers n such that (11^n - 9^n)/2 is prime. 3
5, 31, 271, 929, 2789, 4153 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

All terms are prime.

The corresponding primes: 51001, 95780952266636767336259095696501, ...

LINKS

Table of n, a(n) for n=1..6.

MATHEMATICA

Select[Range[1, 10000], PrimeQ[(11^# - 9^#)/2] &]

PROG

(PARI) for(n=1, 10000, if(isprime((11^n - 9^n)/2), print1(n, ", ")))

CROSSREFS

Cf. A005808, A210506, A128027, A216181, A128347, A273598, A273599, A273600, A062577.

Sequence in context: A058892 A177453 A259787 * A218679 A296967 A292462

Adjacent sequences:  A273598 A273599 A273600 * A273602 A273603 A273604

KEYWORD

nonn,more,hard

AUTHOR

Tim Johannes Ohrtmann, May 26 2016

STATUS

approved

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Last modified May 21 03:05 EDT 2019. Contains 323434 sequences. (Running on oeis4.)