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A342692
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a(n) is the smallest prime p which is greater than the exponent of the n-th Mersenne prime.
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0
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3, 5, 7, 11, 17, 19, 23, 37, 67, 97, 109, 131, 523, 613, 1283, 2207, 2287, 3221, 4259, 4441, 9697, 9949, 11239, 19949, 21713, 23227, 44501, 86249, 110527, 132059, 216103, 756853, 859447, 1257827, 1398281, 2976229, 3021407, 6972607, 13466923, 20996023
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OFFSET
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1,1
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LINKS
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FORMULA
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EXAMPLE
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Terms begin as follows:
. a(n) =
n n-th Mersenne prime exponent q nextprime(q)
- --------------------- ---------- ------------
1 2^2 - 1 = 3 2 3
2 2^3 - 1 = 7 3 5
3 2^5 - 1 = 31 5 7
4 2^7 - 1 = 127 7 11
5 2^13 - 1 = 8191 13 17
6 2^17 - 1 = 131071 17 19
7 2^19 - 1 = 524287 19 23
8 2^31 - 1 = 2147483647 31 37
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MATHEMATICA
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Table[NextPrime[MersennePrimeExponent[n]], {n, 1, 47}]
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CROSSREFS
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KEYWORD
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hard,less,nonn
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AUTHOR
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STATUS
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approved
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