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.

Showing 1-4 of 4 results.

A113334 Values of k in A072532.

Original entry on oeis.org

2, 2, 4, 2, 2, 14, 8, 2, 20, 12, 12, 4, 12, 34, 20, 8, 12, 28, 26, 14, 8, 14, 74, 114, 150, 192, 10, 6, 54, 12, 12, 18, 24, 186, 192, 100, 2, 126, 30, 186
Offset: 1

Views

Author

Zak Seidov, Oct 26 2005

Keywords

Comments

Cf. A072532 a(1)=2, a(n) = smallest prime, larger than a(n-1), of the form k*a(n-1) -1.

Crossrefs

Cf. A072532.

A121799 Values of k from A061092.

Original entry on oeis.org

1, 1, 2, 4, 2, 12, 4, 8, 26, 2, 8, 18, 16, 2, 6, 12, 4, 32, 30, 6, 40, 60, 22, 12, 208, 18, 48, 168, 18, 76, 6, 232, 48, 4, 50, 78, 28, 236, 68, 1026, 10, 162, 6, 138, 162, 48, 120, 330, 82, 414, 130, 188, 164, 6, 6, 100, 126, 10, 36, 40, 48, 94, 14, 218, 954
Offset: 1

Views

Author

Zak Seidov, Oct 26 2005, Dec 14 2006

Keywords

Comments

A061092 is: a(0) = 1; for n>0 a(n) is the smallest prime, larger than a(n-1), of the form k*a(n-1) + 1. - Corrected by Zak Seidov, Oct 03 2015

Links

Crossrefs

Cf. A061092, A072532, A113334.

Programs

  • Mathematica
    a = {2}; b = {1}; Do[k = 1; p = a[[n - 1]]; While[! PrimeQ[k p + 1], k++]; AppendTo[a, k p + 1]; AppendTo[b, k], {n, 2, 60}]; b (* Michael De Vlieger, Oct 03 2015, after Robert G. Wilson v at A061092 *)

Formula

a(n) = (A061092(n)-1)/A061092(n-1). - Zak Seidov, Oct 03 2015

Extensions

Definition corrected by Ken Takusagawa, Jan 17 2006
Corrected and extended by T. D. Noe, Mar 10 2007
Edited by N. J. A. Sloane, Aug 08 2008 at the suggestion of R. J. Mathar

A258081 Values of k in A071580.

Original entry on oeis.org

1, 1, 1, 1, 2, 10, 12, 10, 21, 25, 70, 670, 239, 2115, 586, 1619, 26800, 2505, 99019, 40903, 285641, 67166, 1852765
Offset: 1

Views

Author

Andrew R. Booker, May 19 2015

Keywords

Comments

The first 23 terms were found using gwnum, and the first 22 have been independently checked using gmp.

Links

Crossrefs

Cf. A061092, A072532, A113334.

Programs

  • PARI
    terms=12; p=2; for(n=2, terms, q=p+1; while(!ispseudoprime(q), q=q+p); print1(q\p,", "); p=p*q) \\ Serge Batalov, May 19 2015

A162278 a(0)=1. For n >= 1, a(n) = the smallest prime either of the form a(n-1)*k - 1 or of the form a(n-1)*k + 1, for some k >= 2.

Original entry on oeis.org

1, 2, 3, 5, 11, 23, 47, 281, 563, 2251, 22511, 225109, 450217, 2701301, 10805203, 43220813, 2333923901, 18671391209, 560141736269, 5601417362689, 22405669450757, 448113389015141, 3584907112121129, 186415169830298707
Offset: 0

Views

Author

Leroy Quet, Jun 29 2009

Keywords

Crossrefs

A061092, A072532

Extensions

Extended by R. J. Mathar, Jul 04 2009
Showing 1-4 of 4 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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