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Search: id:A136474
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| A136474 |
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Primes that divide 2^(3^n)+1 for some n. |
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+0
4
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| 3, 19, 163, 1459, 17497, 52489, 87211, 135433, 139483, 1220347
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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This sequence is a subsequence of A057719
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EXAMPLE
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1220347 belongs to the sequence as it is a factor of 2^(3^9)+1 (This is the largest member of the sequence less than 5000000)
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MAPLE
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with(numtheory):L:=3; for p from 5 to 5000000 do if isprime(p) then q:=op(2, ifactors(order(2, p))); if nops(q)=2 then if op(1, op(1, q))=2 and op(2, op(1, q))=1 and op(1, op(2, q))=3 then L:=L, p; fi; fi; fi; od; L;
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CROSSREFS
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Cf. A057719, A136475, A005621, A136473.
Sequence in context: A077046 A054765 A057719 this_sequence A105624 A080835 A080836
Adjacent sequences: A136471 A136472 A136473 this_sequence A136475 A136476 A136477
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KEYWORD
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more,nonn
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AUTHOR
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Chris Smyth (c.smyth(AT)ed.ac.uk), Feb 16 2008
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