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A236169
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Numbers n such that n!*3^n + 1 is prime.
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1
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0, 2, 3, 8, 13, 19, 124, 199, 288, 359, 692, 3610, 5316, 5372, 7442, 8251, 14288, 16883, 17131
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OFFSET
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1,2
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COMMENTS
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a(20) > 25000.
Corresponding primes are all verified prime (i.e., not probable prime): 2, 19, 163, 264539521, 9927882482918401, 141383412854531380076544001, ...
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LINKS
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Table of n, a(n) for n=1..19.
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MATHEMATICA
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Do[f=n!*3^n+1; If[PrimeQ[f], Print[{n, f}]], {n, 0, 25000}]
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PROG
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(PARI) isok(n) = isprime(n!*3^n + 1); \\ Michel Marcus, Jul 23 2017
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CROSSREFS
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Cf. A091415, A002982, A121859.
Sequence in context: A193882 A168343 A217330 * A080478 A002053 A102315
Adjacent sequences: A236166 A236167 A236168 * A236170 A236171 A236172
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KEYWORD
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nonn,more
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AUTHOR
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Robert Price, Jan 19 2014
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EXTENSIONS
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a(1)=0 prepended by Robert Price, Jul 22 2017
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STATUS
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approved
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