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A086678
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Numbers n such that 1 + Sum_{k=1..n} 2k^5 is a prime.
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1
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1, 2, 8, 9, 11, 20, 27, 36, 41, 42, 71, 77, 86, 95, 105, 110, 113, 132, 134, 137, 138, 147, 149, 155, 183, 186, 189, 201, 209, 210, 212, 215, 218, 222, 230, 245, 258, 261, 278, 309, 317, 329, 336, 341, 347, 359, 371, 377, 380, 389, 411, 413, 417, 425, 432, 435
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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FORMULA
| (2*n^6+6*n^5+5*n^4-n^2+6)/6 is prime.
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EXAMPLE
| Sum(k=1,2,2k^5)+1 = 2*1^5+2*2^5 + 1 = 67 is a prime so 2 belongs to the sequence.
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CROSSREFS
| A091872 gives corresponding primes.
Sequence in context: A116039 A030334 A020676 * A066550 A162952 A033950
Adjacent sequences: A086675 A086676 A086677 * A086679 A086680 A086681
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KEYWORD
| nonn,easy
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AUTHOR
| Yalcin Aktar (matheux(AT)msn.com), Jul 28 2003
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EXTENSIONS
| More terms from Ray Chandler (rayjchandler(AT)sbcglobal.net), Aug 07 2003
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