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A064336
Maximal prime numbers with increasing prime differences.
2
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
OFFSET
1,1
LINKS
FORMULA
a(1) = 2, a(n+1) = MAX {prime p | p <= a(n) + p(n)} (where p(n) is the n-th prime number).
EXAMPLE
a(5) = 13, since a(4) = 7, p(4) = 7 and 13 is the largest prime which is not larger than 7 + 7.
MATHEMATICA
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} ]
PROG
(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
CROSSREFS
Cf. A064337.
Sequence in context: A181526 A163487 A048413 * A179921 A211073 A182315
KEYWORD
easy,nonn
AUTHOR
Lior Manor, Sep 13 2001
STATUS
approved