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A049408
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Numbers n such that n^4+n+1 is prime.
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6
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1, 2, 5, 6, 9, 11, 12, 14, 24, 26, 32, 36, 44, 47, 60, 69, 72, 74, 77, 89, 90, 102, 107, 119, 126, 131, 146, 147, 159, 162, 170, 171, 186, 191, 197, 204, 206, 219, 239, 240, 252, 266, 284, 285, 290, 296, 300, 324, 347, 351, 362, 384, 426, 437, 459, 465, 470
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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COMMENTS
| For s = 5,8,11,14,17,20,..., n_s=1+n+n^s is always composite for any n>1. Also for n=1, n_s=3 is a prime for any s. Here we consider the case s=4.
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LINKS
| T. D. Noe, Table of n, a(n) for n=1..1000
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EXAMPLE
| 26 is OK because at s=4, n=26, n_s=1+n+n^s=457003 is a prime.
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PROG
| (PARI) for(n=1, 1000, if(isprime(1+n+n^4), print1(n", ")))
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CROSSREFS
| Cf. A002384, A075723, A049407.
Sequence in context: A166087 A153143 A075724 * A138970 A168550 A187836
Adjacent sequences: A049405 A049406 A049407 * A049409 A049410 A049411
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KEYWORD
| nonn
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
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