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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A062578 Numbers k such that 12^k - 11^k is prime.

Original entry on oeis.org

2, 3, 7, 89, 101, 293, 4463, 70067
Offset: 1

Views

Author

Mike Oakes, May 18 2001, May 19 2001

Keywords

Comments

Terms greater than 1000 may correspond to unproven strong pseudoprimes.

Crossrefs

Cf. A000043, A057468, A059801, A059802, A062572-A062666.

Programs

Extensions

New term 70067 (found in 2006) from Jean-Louis Charton, Sep 02 2009
Edited by M. F. Hasler, Sep 16 2013

A062609 Numbers k such that 43^k - 42^k is prime or a strong pseudoprime.

Original entry on oeis.org

3, 13, 43, 211
Offset: 1

Views

Author

Mike Oakes, May 18 2001, May 19 2001

Keywords

Comments

a(5) > 10^5 - Robert Price, Dec 24 2012

Crossrefs

Cf. A000043, A057468, A059801-A059803, A062572-A062608, A215632, A062611-A062666.

Programs

  • PARI
    forprime(n=1, 9999, ispseudoprime(43^n-42^n) && print1(n", ")) \\ - M. F. Hasler, Sep 21 2013

Extensions

Edited by M. F. Hasler, Sep 21 2013

A062611 Numbers k such that 45^k - 44^k is prime or a strong pseudoprime.

Original entry on oeis.org

2, 5, 151, 223, 313, 1277, 8447
Offset: 1

Views

Author

Mike Oakes, May 18 2001, May 19 2001

Keywords

Comments

a(8) > 10^5. - Robert Price, Jan 02 2013

Crossrefs

Cf. A000043, A057468, A059801-A059803, A062572-A062609, A215632, A062612-A062666.

Programs

  • PARI
    forprime(n=1,9999,ispseudoprime(45^n-44^n)&print1(n",")) \\ - M. F. Hasler, Sep 21 2013

Extensions

Edited by M. F. Hasler, Sep 21 2013

A129737 List of primitive prime divisors of the numbers 4^n-3^n (A005061) in their order of occurrence.

Original entry on oeis.org

7, 37, 5, 11, 71, 13, 14197, 337, 6553, 181, 23, 174659, 193, 131, 500111, 379, 61, 601, 17, 4241, 17050729021, 19, 163, 10814953, 25309, 8861, 8352709, 727, 859, 47, 44483, 17389, 1933, 51361, 1440528320401, 313, 31357, 36174709, 2053, 29, 376853, 59, 349
Offset: 1

Views

Author

N. J. A. Sloane, May 13 2007

Keywords

Comments

Read A005061 term-by-term, factorize each term, write down any primes not seen before.

Links

Crossrefs

Cf. A005061, A129736, A059801, A129733.

A173718 Numbers n such that (9^n - 2^n)/7 is prime.

Original entry on oeis.org

2, 3, 5, 13, 29, 37, 1021, 1399, 2137, 4493, 5521, 108553, 200807
Offset: 1

Views

Author

Robert Price, Dec 22 2012

Keywords

Comments

All terms are prime.
a(14) > 10^6.

Links

Crossrefs

Cf. A004063, A028491, A057468, A059801, A121877, A128024, A128025, A128026, A128027, A128028, A128029, A128030, A128031, A128032.

Programs

  • Mathematica
    Select[ Prime[ Range[1, 100000] ], PrimeQ[ (9^# - 2^#)/7 ]& ]
  • PARI
    is(n)=ispseudoprime((9^n-2^n)/7) \\ Charles R Greathouse IV, Jun 06 2017

Extensions

a(12)-a(13) from Jon Grantham, Jul 29 2023

A188051 Numbers k such that 18^k - 17^k is prime, or a strong pseudoprime.

Original entry on oeis.org

3, 13, 71, 14533, 26641, 48179
Offset: 1

Views

Author

Jean-Louis Charton, Mar 19 2011

Keywords

Comments

Terms < 10000 found by Mike Oakes.
Term 14533 found by Lelio R Paula in June 2008 corresponding to a probable prime with 18243 digits.
Terms 26641 and 48179 found by Jean-Louis Charton in December 2010 corresponding to probable primes with 33442 and 60478 digits.
a(7) > 10^5. - Robert Price, Nov 30 2012

Links

Crossrefs

Cf. A000043, A057468, A059801, A059802, A059803, A062572-A062583, A062585-A062666.

Programs

Extensions

Edited by M. F. Hasler, Sep 21 2013

A215632 Numbers n such that 44^n - 43^n is prime or PRP.

Original entry on oeis.org

37, 283, 62903
Offset: 1

Views

Author

Jean-Louis Charton, Aug 18 2012

Keywords

Comments

No other term <= 68141.
a(4) > 10^5. - Robert Price, Sep 04 2012

Links

Crossrefs

Cf. A000043, A057468, A059801-A059803, A062572-A062609, A062611-A062666.

Programs

Extensions

Edited by M. F. Hasler, Sep 21 2013

A062579 Numbers k such that 13^k - 12^k is prime.

Original entry on oeis.org

17, 31, 41, 47, 109, 163, 643, 2459, 9743, 30271, 87557
Offset: 1

Views

Author

Mike Oakes, May 18 2001, May 19 2001

Keywords

Comments

Terms greater than 1000 may correspond to (unproven) strong pseudoprimes. [Clarified by M. F. Hasler, Sep 16 2013]

Crossrefs

Cf. A000043, A057468, A059801, A059802, A062572-A062666.

Programs

Extensions

Two more terms 30271 and 87557 (found in 2007 and 2008) from Jean-Louis Charton, Sep 02 2009

A062581 Numbers k such that 15^k - 14^k is prime.

Original entry on oeis.org

2, 3, 43, 173, 193, 7559, 165559
Offset: 1

Views

Author

Mike Oakes, May 18 2001, May 19 2001

Keywords

Comments

Terms greater than 1000 may correspond to (unproven) strong pseudoprimes. [Clarified by M. F. Hasler, Sep 16 2013]

Links

Crossrefs

Cf. A000043, A057468, A059801, A059802, A062572-A062666.

Programs

Extensions

a(7) from Jean-Louis Charton, Mar 28 2011

A062582 Numbers k such that 16^k - 15^k is prime.

Original entry on oeis.org

2, 43, 211, 1523, 1579, 1693, 12281, 24889
Offset: 1

Views

Author

Mike Oakes, May 18 2001, May 19 2001

Keywords

Comments

Terms greater than 1000 may correspond to (unproven) strong pseudoprimes.
No other terms less than 100000. - Robert Price, Apr 15 2012

Links

Crossrefs

Cf. A000043, A057468, A059801, A059802, A062572-A062666.

Programs

Extensions

a(7) (found by Mike Oakes in August 2003) and a(8) (found by Jean-Louis Charton in December 2010) from Jean-Louis Charton, Mar 19 2011
Edited by M. F. Hasler, Sep 16 2013
Previous Showing 41-50 of 122 results. Next

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

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