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.

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A126989 Gaps associated with the first and smallest arithmetic progressions of n consecutive primes in A006560.

Original entry on oeis.org

0, 1, 2, 6, 30, 30, 210
Offset: 1

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Author

Artur Jasinski, Jan 01 2007

Keywords

Comments

The gap for the first and smallest AP of 7 consecutive primes is at least 210 (so the 7th term is not definitive).

References

  • P. Ribenboim, The Little Book of Bigger Primes, Springer-Verlag NY 2004.

Crossrefs

Extensions

a(7) corrected by Stephen Tucker, Jan 25 2009

A354484 Common differences associated with the arithmetic progressions of primes in A354376.

Original entry on oeis.org

0, 1, 2, 12, 6, 30, 150, 210, 210, 210, 30030, 13860, 60060, 420420, 4144140, 9699690, 87297210, 717777060, 4180566390, 18846497670, 26004868890
Offset: 1

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Author

Bernard Schott, May 28 2022

Keywords

Comments

Equivalently: Let i, i+d, i+2d, ..., i+(n-1)d be an arithmetic progression of exactly n primes; choose the one which minimizes the last term; then a(n) = common difference d.
The word "exactly" requires both i-d and i+n*d to be nonprime; without "exactly", we get A093364.
For the corresponding values of the first term and the last term, see respectively A354377 and A354376. For the actual arithmetic progressions, see A354485.
The primes in these arithmetic progressions need not be consecutive. (The smallest prime at the start of a run of exactly n consecutive primes in arithmetic progression is A006560(n).)

Examples

			The first few corresponding arithmetic progressions are:
d = 0:   (2);
d = 1:   (2, 3);
d = 2:   (3, 5, 7);
d = 12:  (7, 19, 31, 43);
d = 6:   (5, 11, 17, 23, 29);
d = 30:  (7, 37, 67, 97, 127, 157);
d = 150: (7, 157, 307, 457, 607, 757, 907).
		

References

  • Richard K. Guy, Unsolved Problems in Number Theory, 3rd Edition, Springer, 2004, Section A5, Arithmetic progressions of primes, pp. 25-28.

Crossrefs

Formula

a(1) = 0, then for n > 1, a(n) = (A354376(n) - A354377(n)) / (n-1).

Extensions

a(7)-a(21) via A354376, A354377 from Michael S. Branicky, May 28 2022

A093366 Gaps associated with the arithmetic progressions in A093365.

Original entry on oeis.org

0, 3, 3, 8, 8, 12, 24, 24, 24, 24, 24, 84, 84, 84, 84, 84, 84, 84, 84, 84, 84, 2772, 21252, 21252, 21252, 42504, 42504, 63756, 63756, 63756, 825132, 825132, 825132
Offset: 1

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Author

Hugo Pfoertner, Apr 27 2004

Keywords

Crossrefs

Extensions

Erroneous terms a(31) and a(32) corrected by Hugo Pfoertner, Oct 15 2010

A122764 Initial terms of arithmetic progression of primes in A005115 with duplicates removed.

Original entry on oeis.org

2, 3, 5, 7, 199, 110437, 4943, 31385539, 115453391, 53297929, 3430751869, 4808316343, 8297644387, 214861583621, 5749146449311
Offset: 1

Views

Author

Roger L. Bagula, Sep 22 2006

Keywords

Comments

Old title was: "In A005115 a+b*j: the a term with duplicates removed."
If duplicate terms are not removed, we obtain A113827. - Charlie Neder, Feb 02 2019

Examples

			A005115(7) comes from the 7-term prime progression {7, 157, 307, 457, 607, 757, 907}, and so 7 is in this sequence. - _Charlie Neder_, Feb 02 2019
		

Crossrefs

Programs

  • Mathematica
    a = {{ 1, 2, 2}, {2, 2 + j, 3}, {3, 3 + 2j, 7}, {4, 5 + 6j, 23}, {5, 5 + 6j, 29}, {6, 7 + 30j, 157}, {7, 7 + 150j, 907}, {8, 199 + 210j, 1669}, {9, 199 + 210j, 1879}, {10, 199 + 210j, 2089}, {11, 110437 + 13860j, 249037}, {12, 110437 + 13860j, 262897}}
    Union[Table[CoefficientList[a[[n, 2]], j][[1]], {n, 1, 12}]]

Extensions

Better name and a(7)-a(15) from Charlie Neder, Feb 02 2019
Previous Showing 11-14 of 14 results.