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A064336
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Maximal prime numbers with increasing prime differences.
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2
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2, 3, 5, 7, 13, 23, 31, 47, 61, 83, 109, 139, 173, 211, 251, 293, 337, 389, 449, 509, 577, 647, 719, 797, 883, 977, 1069, 1171, 1277, 1381, 1493, 1619, 1747, 1879, 2017, 2161, 2311, 2467, 2621, 2777, 2939, 3109, 3271, 3461, 3643, 3833, 4027, 4231, 4451, 4673
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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(1) = 2, a(n+1) = MAX {prime p | p <= a(n) + p(n)} (where p(n) is the n-th prime number).
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EXAMPLE
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a(5) = 13, since a(4) = 7, p(4) = 7 and 13 is the largest prime which is not larger than 7 + 7.
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MATHEMATICA
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PrevPrime[n_] := (k = n; While[ ! PrimeQ[k], k-- ]; k); f[1] = 2; f[n_] := PrevPrime[ f[n - 1] + Prime[n] ]; Table[ f[n], {n, 1, 50} ]
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PROG
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(PARI) { for (n=1, 1000, if (n>1, a=precprime(a + prime(n - 1)), a=2); write("b064336.txt", n, " ", a) ) } \\ Harry J. Smith, Sep 12 2009
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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STATUS
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approved
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