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A075716 1+n+n^s is a prime, s=15. +0
3
1, 2, 30, 32, 35, 54, 62, 77, 101, 120, 138, 161, 171, 186, 210, 234, 269, 285, 311, 341, 362, 368, 374, 467, 476, 486, 531, 567, 578, 720, 737, 740, 780, 806, 824, 932, 990, 1035, 1037, 1041, 1049, 1067, 1089, 1136, 1137, 1146, 1167, 1202, 1251, 1269 (list; graph; listen)
OFFSET

1,2

COMMENT

For s = 5,8,11,14,17,20,..., n_s=1+n+n^s is always composite for any n>1. Also at n=1, n_s=3 is a prime for any s. So it is interesting to consider only the cases of s =/= 5,8,11,14,17,20,... and n>1. Here i consider the case s=15 and find several first n's making n_s a prime (or a probable prime).

EXAMPLE

2 is OK because at s=15, n=2, n_s=1+n+n^s=32771 is a prime.

PROGRAM

(PARI) for(n=1, 1000, if(isprime(1+n+n^15), print1(n", ")))

CROSSREFS

Cf. A002384, A075715, A075717.

Sequence in context: A058988 A078690 A071056 this_sequence A022377 A145290 A127026

Adjacent sequences: A075713 A075714 A075715 this_sequence A075717 A075718 A075719

KEYWORD

nonn

AUTHOR

Zak Seidov (zakseidov(AT)yahoo.com), Oct 03 2002

EXTENSIONS

More terms from R. Stephan (ralf(AT)ark.in-berlin.de), Apr 05 2003

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Last modified November 27 22:38 EST 2009. Contains 167602 sequences.


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