cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A064337 Minimal prime numbers with increasing prime differences.

Original entry on oeis.org

2, 5, 11, 17, 29, 41, 59, 79, 101, 127, 157, 191, 229, 271, 317, 367, 421, 487, 557, 631, 709, 787, 877, 967, 1061, 1163, 1277, 1381, 1489, 1601, 1721, 1861, 1993, 2131, 2273, 2423, 2579, 2741, 2909, 3079, 3253, 3433, 3617, 3821, 4019, 4217, 4421, 4637
Offset: 1

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Author

Lior Manor, Sep 13 2001

Keywords

Examples

			a(5) = 29, since a(4) = 17, p(4) = 7 and 29 is the smallest prime which is not smaller than 17 + 7.
		

Crossrefs

Cf. A064336.

Programs

  • Mathematica
    NextPrime[n_] := (k = n; While[ ! PrimeQ[k], k++ ]; k); f[1] = 2; f[n_] := NextPrime[ f[n - 1] + Prime[n-1] ]; Table[ f[n], {n, 1, 50} ]
    Transpose[NestList[{First[#]+1,NextPrime[Last[#]+Prime[First[#]]]}&, {1,2}, 50]][[2]] (* Harvey P. Dale, Oct 23 2011 *)
  • PARI
    for (n=1, 1000, if (n>1, a=nextprime(a + prime(n - 1)), a=2); write("b064337.txt", n, " ", a) )  \\ Harry J. Smith, Sep 12 2009

Formula

a(1) = 2, a(n+1) = MIN {prime p | p >= a(n) + prime(n)} (where prime(n) is the n-th prime number).
Conjecture: a(n) ~ K*n^2*log(n). - Bill McEachen, Apr 04 2024
a(n) >= A007504(n) >> n^2 log n. On Cramér's conjecture, a(n) << n^2 log^2 n. - Charles R Greathouse IV, Apr 10 2024