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.

A243894 a(n) = prime(k+1) with k = n^2 + prime(n)^2.

Original entry on oeis.org

13, 43, 149, 317, 853, 1277, 2281, 2957, 4507, 7433, 8693, 12671, 15887, 17839, 21701, 28099, 35407, 38327, 46997, 53359, 56911, 67511, 75289, 87541, 105173, 115067, 120473, 130829, 136573, 147919, 189139, 202519, 223009, 230449, 267413, 275711
Offset: 1

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Author

Freimut Marschner, Jun 14 2014

Keywords

Comments

The prime numbers prime(k-1) = A243893, prime(k) = A243892 and a(n) = prime(k+1) with k = n^2 + prime(n)^2 are forming a triple of successive prime numbers.

Examples

			n=1, n^2 = 1, prime(1) = 2, 2^2 = 4, 1 + 4 = 5, 5 + 1 = 6, prime(6) = 13 ;
n=2, n^2 = 4, prime(2) = 3, 3^2 = 9, 4 + 9 = 13, 13 + 1 = 14, prime(14) = 43.
		

Crossrefs

Cf. A000290 (squares n^2), A000040 (prime(n)), A001248 (prime(n)^2), A106587 (n^2 + prime(n)^2).

Programs

  • Mathematica
    Table[Prime[n^2+Prime[n]^2+1],{n,40}] (* Harvey P. Dale, Dec 31 2015 *)
  • PARI
    vector(40, n, prime(n^2 + prime(n)^2 + 1)) \\ Colin Barker, Jun 14 2014

Formula

a(n) = prime((n^2 + prime(n)^2) + 1) = prime(A106587(n) + 1).