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A073715
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Prime preceding the n-th Mersenne prime.
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4
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2, 5, 29, 113, 8179, 131063, 524269, 2147483629, 2305843009213693921, 618970019642690137449562091, 162259276829213363391578010287957, 170141183460469231731687303715884105703
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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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a(n) = prime(primepi(A000668(n))-1).
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MATHEMATICA
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NextPrime[Select[2^Prime[Range[50]] - 1, PrimeQ], -1] (* Jayanta Basu, Jul 08 2013 *)
Table[NextPrime[2^MersennePrimeExponent[n] - 1, -1], {n, 1, 12}] (* Amiram Eldar, Aug 10 2024 *)
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CROSSREFS
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KEYWORD
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nonn,hard
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AUTHOR
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STATUS
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approved
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