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.

Previous Showing 11-15 of 15 results.

A219047 Numbers k such that 3^k - 28 is prime.

Original entry on oeis.org

4, 6, 10, 15, 22, 24, 27, 35, 63, 91, 95, 96, 124, 132, 220, 280, 338, 372, 432, 568, 692, 738, 1144, 1168, 1698, 2080, 2138, 2710, 2895, 2984, 3536, 3816, 4462, 4972, 6588, 6666, 10350, 58991, 68854, 145806, 163500, 196192
Offset: 1

Views

Author

Nicolas M. Perrault, Nov 10 2012

Keywords

Comments

a(43) > 2*10^5. - Robert Price, Dec 10 2013

Examples

			3^4 - 28 = 53 (prime), so 4 is in the sequence.

Crossrefs

Cf. Sequences of numbers k such that 3^k + m is prime:
(m = 2) A051783, (m = -2) A014224, (m = 4) A058958, (m = -4) A058959,
(m = 8) A217136, (m = -8) A217135, (m = 10) A217137, (m = -10) A217347,
(m = 14) A219035, (m = -14) A219038, (m = 16) A205647, (m = -16) A219039,
(m = 20) A219040, (m = -20) A219041, (m = 22) A219042, (m = -22) A219043,
(m = 26) A219044, (m = -26) A219045, (m = 28) A219046, (m = -28) A219047,
(m = 32) A219048, (m = -32) A219049, (m = 34) A219050, (m = -34) A219051. Note that if m is a multiple of 3, 3^k + m is also a multiple of 3 (for k greater than 0), and as such isn't prime.

Programs

  • Mathematica
    Do[If[PrimeQ[3^n - 28], Print[n]], {n, 10000}]
  • PARI
    is(n)=isprime(3^n-28) \\ Charles R Greathouse IV, Feb 17 2017

Extensions

a(37)-a(42) from Robert Price, Dec 10 2013

A219048 Numbers k such that 3^k + 32 is prime.

Original entry on oeis.org

2, 3, 4, 6, 23, 24, 38, 164, 172, 176, 207, 216, 251, 272, 424, 1112, 1318, 2072, 2664, 3143, 4704, 5236, 9526, 13064, 13523, 27111, 35931, 37504, 47542, 128656, 181551
Offset: 1

Views

Author

Nicolas M. Perrault, Nov 10 2012

Keywords

Comments

a(32) > 2*10^5. - Robert Price, Nov 15 2013

Examples

			For k = 2, 3^2 + 32 = 41 (prime). Hence k = 2 is in the sequence.

Crossrefs

Cf. Sequences of numbers k such that 3^k + m is prime:
(m = 2) A051783, (m = -2) A014224, (m = 4) A058958, (m = -4) A058959,
(m = 8) A217136, (m = -8) A217135, (m = 10) A217137, (m = -10) A217347,
(m = 14) A219035, (m = -14) A219038, (m = 16) A205647, (m = -16) A219039,
(m = 20) A219040, (m = -20) A219041, (m = 22) A219042, (m = -22) A219043,
(m = 26) A219044, (m = -26) A219045, (m = 28) A219046, (m = -28) A219047,
(m = 32) A219048, (m = -32) A219049, (m = 34) A219050, (m = -34) A219051. Note that if m is a multiple of 3, 3^k + m is also a multiple of 3 (for k greater than 0), and as such isn't prime.

Programs

  • Mathematica
    Do[If[PrimeQ[3^n + 32], Print[n]], {n, 10000}]
  • PARI
    is(n)=isprime(3^n+32) \\ Charles R Greathouse IV, Feb 17 2017

Extensions

a(23)-a(31) from Robert Price, Nov 15 2013

A219049 Numbers k such that 3^k - 32 is prime.

Original entry on oeis.org

5, 8, 18, 21, 69, 84, 181, 216, 461, 642, 672, 2413, 3681, 5666, 12281, 14949, 19508, 27817, 34061, 43236, 43733, 81828
Offset: 1

Views

Author

Nicolas M. Perrault, Nov 10 2012

Keywords

Comments

a(23) > 2*10^5. - Robert Price, Dec 22 2013

Examples

			3^5 - 32 = 211 (prime), so 5 is in the sequence.

Crossrefs

Cf. Sequences of numbers k such that 3^k + m is prime:
(m = 2) A051783, (m = -2) A014224, (m = 4) A058958, (m = -4) A058959,
(m = 8) A217136, (m = -8) A217135, (m = 10) A217137, (m = -10) A217347,
(m = 14) A219035, (m = -14) A219038, (m = 16) A205647, (m = -16) A219039,
(m = 20) A219040, (m = -20) A219041, (m = 22) A219042, (m = -22) A219043,
(m = 26) A219044, (m = -26) A219045, (m = 28) A219046, (m = -28) A219047,
(m = 32) A219048, (m = -32) A219049, (m = 34) A219050, (m = -34) A219051. Note that if m is a multiple of 3, 3^k + m is also a multiple of 3 (for k greater than 0), and as such isn't prime.

Programs

  • Mathematica
    Do[If[PrimeQ[3^n - 32], Print[n]], {n, 10000}]
  • PARI
    is(n)=isprime(3^n-32) \\ Charles R Greathouse IV, Feb 17 2017

Extensions

a(15)-a(22) from Robert Price, Dec 22 2013

A219050 Numbers k such that 3^k + 34 is prime.

Original entry on oeis.org

1, 2, 3, 5, 7, 9, 10, 17, 27, 34, 51, 57, 61, 89, 98, 171, 547, 569, 769, 874, 1105, 2198, 2307, 3937, 4685, 5105, 5582, 11131, 11821, 15902, 24626, 36401, 46195, 50974, 65198, 66685
Offset: 1

Views

Author

Nicolas M. Perrault, Nov 10 2012

Keywords

Comments

a(37) > 2*10^5. - Robert Price, Nov 24 2013

Examples

			For k = 2, 3^2 + 34 = 43 (prime), so 2 is in the sequence.

Crossrefs

Cf. Sequences of numbers k such that 3^k + m is prime:
(m = 2) A051783, (m = -2) A014224, (m = 4) A058958, (m = -4) A058959,
(m = 8) A217136, (m = -8) A217135, (m = 10) A217137, (m = -10) A217347,
(m = 14) A219035, (m = -14) A219038, (m = 16) A205647, (m = -16) A219039,
(m = 20) A219040, (m = -20) A219041, (m = 22) A219042, (m = -22) A219043,
(m = 26) A219044, (m = -26) A219045, (m = 28) A219046, (m = -28) A219047,
(m = 32) A219048, (m = -32) A219049, (m = 34) A219050, (m = -34) A219051. Note that if m is a multiple of 3, 3^k + m is also a multiple of 3 (for k greater than 0), and as such isn't prime.

Programs

  • Mathematica
    Do[If[PrimeQ[3^n + 34], Print[n]], {n, 10000}]
  • PARI
    is(n)=isprime(3^n+34) \\ Charles R Greathouse IV, Feb 17 2017

Extensions

a(28)-a(36) from Robert Price, Nov 24 2013

A289984 Primes of the form 3^k - 34.

Original entry on oeis.org

47, 2153, 177113, 1594289, 68630377364849, 1853020188851807, 150094635296999087, 984770902183611232847, 49269609804781974438694403402127765833, 809164816771822689786320611221860560835816670552324143733808294394923420529
Offset: 1

Views

Author

Robert Price, Sep 02 2017

Keywords

Links

Crossrefs

Cf. A000040, A219051 (corresponding k's).

Programs

  • Mathematica
    Select[Table[3^k - 34, {k, 4, 100}], PrimeQ[#] &]

Formula

a(n) = 3^A219051(n) - 34. - Elmo R. Oliveira, Nov 12 2023
Previous Showing 11-15 of 15 results.

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