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 1-10 of 16 results. Next

A082103 Numbers n such that 3^n + 2^(n-1) is prime.

Original entry on oeis.org

2, 3, 4, 6, 7, 8, 10, 15, 21, 24, 36, 49, 51, 86, 116, 134, 176, 284, 345, 498, 544, 649, 844, 1051, 1171, 1384, 1497, 1514, 1638, 1856, 2860, 2890, 3235, 3584, 4047, 5990, 7729, 8935, 9907, 15241, 15864, 17629, 19264, 28239, 43730, 46879, 65379, 89468, 128787, 139976
Offset: 1

Views

Author

Labos Elemer, Apr 14 2003

Keywords

Comments

a(51) > 2*10^5. - Robert Price, May 06 2016

Examples

			n=4: 89 = 2*2*2 + 3*3*3*3 is prime.
n=15: 3^15 + 2^14 = 14365291 is prime.

Crossrefs

Cf. A082101, A082102, A095906, A093717, A093793, A093765, A096185, A093794, A093795, A096186.

Programs

Extensions

Edited and extended by Robert G. Wilson v, May 25 2004
Edited by N. J. A. Sloane, Sep 15 2008 at the suggestion of R. J. Mathar
a(37)-a(50) from Robert Price, May 06 2016

A093794 Numbers n such that 8^n+7^(n-1) is prime.

Original entry on oeis.org

2, 14, 30, 56, 96, 192, 200, 462, 540, 1400, 2756, 9030, 99702
Offset: 1

Views

Author

Herman H. Rosenfeld (herm3(AT)pacbell.net), May 18 2004

Keywords

Comments

a(14) > 10^5. - Robert Price, Feb 18 2016

Examples

			14 is a member since 814+712 = 4494935521511 which is a prime number.

Crossrefs

Cf. A082103, A093717, A093793, A093765, A096185, A093794, A093795, A096186.

Programs

  • Mathematica
    Do[ If[ PrimeQ[8^n + 7^(n - 1)], Print[n]], {n, 4000}]
  • PARI
    is(n)=isprime(8^n+7^(n-1)) \\ Charles R Greathouse IV, Feb 17 2017

Extensions

More terms from Robert G. Wilson v, Jun 18 2004
a(12)-a(13) from Robert Price, Feb 18 2016

A093795 Numbers k such that 9^k + 8^(k-1) is prime.

Original entry on oeis.org

2, 7, 8, 31, 610, 1292, 4015, 5990, 8887, 9626, 57952, 62116, 84698
Offset: 1

Views

Author

Herman H. Rosenfeld (herm3(AT)pacbell.net), May 18 2004

Keywords

Comments

a(14) > 10^5. - Robert Price, Mar 05 2016

Examples

			8 is a term since 9^8 + 8^7 = 45143873, which is a prime number.

Crossrefs

Cf. A082103, A093717, A093793, A093765, A096185, A093794, A093795, A096186.

Programs

  • Mathematica
    Do[ If[ PrimeQ[9^n + 8^(n - 1)], Print[n]], {n, 4000}]
  • PARI
    is(n)=isprime(9^n+8^(n-1)) \\ Charles R Greathouse IV, Feb 17 2017

Extensions

More terms from Robert G. Wilson v, Jun 18 2004
a(7)-a(13) from Robert Price, Mar 05 2016

A096186 Numbers k such that 10^k+9^(k-1) is prime.

Original entry on oeis.org

1, 2, 4, 9, 12, 14, 19, 26, 28, 72, 79, 273, 565, 990, 1166, 2205, 4212, 5340, 5562, 9877, 10297, 14316, 35908, 48410, 61525
Offset: 1

Views

Author

Herman H. Rosenfeld (herm3(AT)pacbell.net) and Robert G. Wilson v, Jun 21 2004

Keywords

Comments

a(26) > 10^5. - Robert Price, Mar 28 2016

Crossrefs

Cf. A082103, A093717, A093793, A093765, A096185, A093794, A093795, A096186.

Programs

  • Mathematica
    Do[ If[ PrimeQ[10^n + 9^(n - 1)], Print[n]], {n, 4000}]
  • PARI
    is(n)=isprime(10^n+9^(n-1)) \\ Charles R Greathouse IV, Feb 17 2017

Extensions

a(17)-a(25) from Robert Price, Mar 28 2016

A093717 Numbers n such that 4^n+3^(n-1) is prime.

Original entry on oeis.org

1, 2, 3, 4, 6, 8, 10, 12, 15, 19, 27, 30, 32, 34, 43, 48, 51, 72, 88, 106, 906, 963, 1328, 1336, 1611, 1664, 2680, 3122, 3267, 5323, 6499, 7870, 32836, 37846, 38456, 41912, 45238, 51991, 63530, 68704
Offset: 1

Views

Author

Herman H. Rosenfeld (herm3(AT)pacbell.net), May 17 2004

Keywords

Comments

a(41) > 10^5. - Robert Price, Apr 11 2016

Examples

			19 is a member since 4^19 + 3^18 = 2388583837526729, which is a prime number.

Crossrefs

Cf. A082103, A093793, A093765, A096185, A093794, A093795, A096186.

Programs

  • Mathematica
    Select[Range[1000], PrimeQ[4^# + 3^(# - 1)] &]
  • PARI
    is(n)=isprime(4^n+3^(n-1)) \\ Charles R Greathouse IV, Feb 17 2017

Extensions

More terms from Robert G. Wilson v, Jun 18 2004
a(30)-a(40) from Robert Price, Apr 11 2016

A093793 Numbers n such that 5^n+4^(n-1) is prime.

Original entry on oeis.org

2, 6, 22, 94, 622, 910, 1058, 1306, 4430, 18914, 23654, 35630, 52846, 63498, 85630
Offset: 1

Views

Author

Herman H. Rosenfeld (herm3(AT)pacbell.net), May 17 2004

Keywords

Comments

a(16) > 10^5. - Robert Price, Mar 08 2016

Examples

			22 is a member since 522+421 = 2388583837526729 which is a prime number.

Crossrefs

Cf. A082103, A093717, A093765, A096185, A093794, A093795, A096186.

Programs

  • Mathematica
    Do[ If[ PrimeQ[5^n + 4^(n - 1)], Print[n]], {n, 5000}]
  • PARI
    is(n)=isprime(5^n+4^(n-1)) \\ Charles R Greathouse IV, Feb 17 2017

Extensions

More terms from Robert G. Wilson v, Jun 18 2004
a(10)-a(15) from Robert Price, Mar 08 2016

A096185 Numbers k such that 7^k + 6^(k-1) is prime.

Original entry on oeis.org

3, 4, 8, 9, 16, 25, 33, 40, 116, 201, 208, 504, 579, 964, 1060, 1160, 1508, 1969, 4615, 7311, 65964, 83121, 87396
Offset: 1

Views

Author

Herman H. Rosenfeld (herm3(AT)pacbell.net) and Robert G. Wilson v, Jun 18 2004

Keywords

Comments

a(24) > 10^5. - Robert Price, Mar 23 2016

Crossrefs

Cf. A082103, A093717, A093793, A093765, A093794, A093795, A096186.

Programs

  • Mathematica
    Do[ If[ PrimeQ[7^n + 6^(n - 1)], Print[n]], {n, 4000}]
  • PARI
    lista(nn) = {for(n=1, nn, if(ispseudoprime(7^n+6^(n-1)), print1(n, ", "))); } \\ Altug Alkan, Mar 23 2016

Extensions

a(19)-a(23) from Robert Price, Mar 23 2016

A093713 Numbers k such that 6^k - 5^(k-1) is prime.

Original entry on oeis.org

1, 2, 3, 4, 5, 12, 16, 18, 21, 42, 66, 69, 123, 132, 165, 204, 397, 401, 486, 657, 1005, 1050, 1882, 2545, 2813, 3168, 4092, 4151, 4469, 5358, 9168, 11554, 11866, 80946
Offset: 1

Views

Author

Herman H. Rosenfeld (herm3(AT)pacbell.net) and Robert G. Wilson v, Jun 17 2004

Keywords

Comments

a(35) > 10^5. - Robert Price, May 04 2016

Crossrefs

Cf. A093765.

Programs

  • Mathematica
    Do[ If[ PrimeQ[6^n - 5^(n - 1)], Print[n]], {n, 2000}]
  • PARI
    is(n)=isprime(6^n-5^(n-1)) \\ Charles R Greathouse IV, Feb 17 2017

Extensions

a(24)-a(34) from Robert Price, May 04 2016

A269227 Numbers n such that 7^n + 6^(n + 1) is prime.

Original entry on oeis.org

0, 1, 4, 5, 12, 16, 27, 87, 252, 1052, 1691, 3237, 3669, 16140, 17072, 27932, 70811
Offset: 1

Views

Author

Robert Price, Jul 11 2016

Keywords

Comments

a(18) > 10^5.

Crossrefs

Cf. A093765.

Programs

  • Magma
    [n: n in [0..500] | IsPrime(7^n+6^(n+1))]; // Vincenzo Librandi, Jul 12 2016
  • Mathematica
    Select[Range[0,100000], PrimeQ[7^# + 6^(# + 1)] &]
  • PARI
    is(n)=ispseudoprime(7^n+6^(n+1)) \\ Charles R Greathouse IV, Jun 13 2017

A272621 Numbers n such that 10^n-9^(n-1) is prime.

Original entry on oeis.org

3, 9, 15, 155, 217, 281, 287, 491, 563, 581, 983, 2243, 4375, 8409, 98669
Offset: 1

Views

Author

Robert Price, May 03 2016

Keywords

Comments

a(16) > 10^5.

Examples

			3 is a member since 10^3-9^2 = 1000-81 = 919 which is a prime number.

Crossrefs

Cf. A093713, A082103, A093717, A093793, A096185, A093765, A093794, A093795, A096186.

Programs

  • Mathematica
    Select[Range[0, 100000], PrimeQ[10^# - 9^(# - 1)] &]
  • PARI
    is(n)=ispseudoprime(10^n-9^(n-1)) \\ Charles R Greathouse IV, Jun 13 2017
Showing 1-10 of 16 results. Next

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

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