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 1-6 of 6 results.

A255387 Primes of the form 141^k - 140^k.

Original entry on oeis.org

281, 59221, 769449701919846533025514621
Offset: 1

Views

Author

Michael P. May, Feb 21 2015

Keywords

Comments

a(4) has 372 digits. - Vincenzo Librandi, Feb 22 2015
The values of k are 2, 3, 13, 173, ... - Jinyuan Wang, May 30 2020

Crossrefs

Cf. A254298.

Programs

  • Magma
    [a: n in [0..600] | IsPrime(a) where a is 141^n-140^n]; // Vincenzo Librandi, Feb 22 2015
    
  • Mathematica
    Select[Table[141^n - 140^n, {n, 1000}], PrimeQ] (* Vincenzo Librandi, Feb 22 2015 *)
  • PARI
    select(m->ispseudoprime(m), vector(20, k, 141^k-140^k)) \\ Jinyuan Wang, May 30 2020

A255388 Primes of the form 157^k - 156^k.

Original entry on oeis.org

313, 73477, 102850464108757, 2202194587566133922938215539676032221
Offset: 1

Views

Author

Michael P. May, Feb 21 2015

Keywords

Comments

a(5) has 1452 digits. - Vincenzo Librandi, Feb 22 2015
The values of k are 2, 3, 7, 17, 661, ... - Jinyuan Wang, May 30 2020

Crossrefs

Cf. A254298.

Programs

  • Magma
    [a: n in [0..600] | IsPrime(a) where a is 157^n-156^n]; // Vincenzo Librandi, Feb 22 2015
  • Mathematica
    Select[Table[157^n - 156^n, {n, 1000}], PrimeQ] (* Vincenzo Librandi, Feb 22 2015 *)

A255389 Primes of the form 166^k - 165^k.

Original entry on oeis.org

331, 82171, 3751197451
Offset: 1

Views

Author

Michael P. May, Feb 21 2015

Keywords

Comments

a(4) has 1641 digits and a(5) has 1717 digits. - Vincenzo Librandi, Feb 22 2015
The values of k are 2, 3, 5, 739, 773, ... - Jinyuan Wang, May 30 2020

Crossrefs

Cf. A254298.

Programs

  • Magma
    [a: n in [0..600] | IsPrime(a) where a is 166^n-165^n]; // Vincenzo Librandi, Feb 22 2015
    
  • Mathematica
    Select[Table[166^n - 165^n, {n, 1000}], PrimeQ] (* Vincenzo Librandi, Feb 22 2015 *)
  • PARI
    select(m->ispseudoprime(m), vector(10, k, 166^k-165^k)) \\ Jinyuan Wang, May 30 2020

A255390 Primes of the form 173^k - 172^k.

Original entry on oeis.org

89269, 184438202074309, 379889466040169687349246148321558634248221737128245658182879616485078366262882828905566134219669
Offset: 1

Views

Author

Michael P. May, Feb 21 2015

Keywords

Comments

a(4) has 1569 digits, a(5) has 2030 digits. - Vincenzo Librandi, Feb 22 2015
The values of k are 3, 7, 43, 701, 907, ... - Jinyuan Wang, May 30 2020

Crossrefs

Cf. A254298.

Programs

  • Magma
    [a: n in [0..200] | IsPrime(a) where a is (173^n-172^n)]; // Vincenzo Librandi, Feb 22 2015
    
  • Mathematica
    Select[Table[173^n - 172^n, {n, 1000}], PrimeQ] (* Vincenzo Librandi, Feb 22 2015 *)
  • PARI
    select(m->ispseudoprime(m), vector(100, k, 173^k-172^k)) \\ Jinyuan Wang, May 30 2020

A259530 Numbers k such that 136^k - 135^k is prime.

Original entry on oeis.org

2, 7, 53, 103, 1171, 1699, 5953, 29131
Offset: 1

Views

Author

Michael P. May, Jun 29 2015

Keywords

Crossrefs

Cf. A254298.

Programs

Extensions

a(5)-a(6) from Vincenzo Librandi, Jul 01 2015
a(7) from Tim Johannes Ohrtmann, Mar 16 2018
a(8) from Michael S. Branicky, Oct 14 2024

A259535 Numbers k such that 159^k - 158^k is prime.

Original entry on oeis.org

2, 3, 17, 107, 13313
Offset: 1

Views

Author

Michael P. May, Jun 29 2015

Keywords

Comments

a(5) is only a strong pseudoprime. - Tim Johannes Ohrtmann, Jun 20 2016
a(6) > 30000. - Michael S. Branicky, Oct 15 2024

Crossrefs

Cf. A254298.

Programs

Extensions

a(4) from Vincenzo Librandi, Jul 01 2015
a(5) from Tim Johannes Ohrtmann, Jun 20 2016
Showing 1-6 of 6 results.