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 1-9 of 9 results.

A228026 Primes of the form 4^k + 3.

Original entry on oeis.org

7, 19, 67, 4099, 65539, 262147, 268435459, 1073741827, 19342813113834066795298819
Offset: 1

Views

Author

Vincenzo Librandi, Aug 11 2013

Keywords

Examples

			67 is a term because 4^3 + 3 = 67 is prime.
		

Crossrefs

Cf. A089437 (associated k).
Cf. Primes of the form r^k + h: A092506 (r=2, h=1), A057733 (r=2, h=3), A123250 (r=2, h=5), A104066 (r=2, h=7), A104070 (r=2, h=9), A057735 (r=3, h=2), A102903 (r=3, h=4), A102870 (r=3, h=8), A102907 (r=3, h=10), A290200 (r=4, h=1), this sequence (r=4, h=3), A228027 (r=4, h=9), A182330 (r=5, h=2), A228029 (r=5, h=6), A102910 (r=5, h=8), A182331 (r=6, h=1), A104118 (r=6, h=5), A104115 (r=6, h=7), A104065 (r=7, h=4), A228030 (r=7, h=6), A228031 (r=7, h=10), A228032 (r=8, h=3), A228033 (r=8, h=5), A144360 (r=8, h=7), A145440 (r=8, h=9), A228034 (r=9, h=2), A159352 (r=10, h=3), A159031 (r=10, h=7).

Programs

  • Magma
    [a: n in [0..200] | IsPrime(a) where a is  4^n+3];
  • Mathematica
    Select[Table[4^n + 3, {n, 0, 200}], PrimeQ]

Formula

a(n) = 4^A089437(n) + 3. - Elmo R. Oliveira, Nov 14 2023

Extensions

Cross-references corrected by Robert Price, Aug 01 2017

A228032 Primes of the form 8^n + 3.

Original entry on oeis.org

11, 67, 4099, 32771, 262147, 1073741827, 19342813113834066795298819
Offset: 1

Views

Author

Vincenzo Librandi, Aug 11 2013

Keywords

Crossrefs

Cf. A217354 (associated n).
Cf. Primes of the form k^n + h: A092506 (k=2, h=1), A057733 (k=2, h=3), A123250 (k=2, h=5), A104066 (k=2, h=7), A104070 (k=2, h=9), A057735 (k=3, h=2), A102903 (k=3, h=4), A102870 (k=3, h=8), A102907 (k=3, h=10), A290200 (k=4, h=1), A182330 (k=5, h=2), A102910 (k=5, h=8), A182331 (k=6, h=1), A104118 (k=6, h=5), A104115 (k=6, h=7), A104065 (k=7, h=4), this sequence (k=8, h=3), A144360 (k=8, h=7), A145440 (k=8, h=9), A228034 (k=9, h=2), A159352 (k=10, h=3), A159031 (k=10, h=7).

Programs

  • Magma
    [a: n in [0..300] | IsPrime(a) where a is  8^n+3];
  • Mathematica
    Select[Table[8^n + 3, {n, 0, 300}], PrimeQ]

Extensions

Corrected cross-references - Robert Price, Aug 01 2017

A228029 Primes of the form 5^n + 6.

Original entry on oeis.org

7, 11, 31, 131, 631, 1220703131
Offset: 1

Views

Author

Vincenzo Librandi, Aug 11 2013

Keywords

Crossrefs

Cf. A089142 (associated n).
Cf. Primes of the form k^n + h: A092506 (k=2, h=1), A057733 (k=2, h=3), A123250 (k=2, h=5), A104066 (k=2, h=7), A104070 (k=2, h=9), A057735 (k=3, h=2), A102903 (k=3, h=4), A102870 (k=3, h=8), A102907 (k=3, h=10), A290200 (k=4, h=1), A182330 (k=5, h=2), this sequence (k=5, h=6), A102910 (k=5, h=8), A182331 (k=6, h=1), A104118 (k=6, h=5), A104115 (k=6, h=7), A104065 (k=7, h=4), A144360 (k=8, h=7), A145440 (k=8, h=9), A228034 (k=9, h=2), A159352 (k=10, h=3), A159031 (k=10, h=7).

Programs

  • Magma
    [a: n in [0..200] | IsPrime(a) where a is  5^n+6];
  • Mathematica
    Select[Table[5^n + 6, {n, 0, 200}], PrimeQ]

Extensions

Corrected cross-references - Robert Price, Aug 01 2017

A228030 Primes of the form 7^n + 6.

Original entry on oeis.org

7, 13, 349, 33232930569607, 2651730845859653471779023381607
Offset: 1

Views

Author

Vincenzo Librandi, Aug 11 2013

Keywords

Crossrefs

Cf. A217130 (associated n).
Cf. Primes of the form k^n + h: A092506 (k=2, h=1), A057733 (k=2, h=3), A123250 (k=2, h=5), A104066 (k=2, h=7), A104070 (k=2, h=9), A057735 (k=3, h=2), A102903 (k=3, h=4), A102870 (k=3, h=8), A102907 (k=3, h=10), A290200 (k=4, h=1), A182330 (k=5, h=2), A102910 (k=5, h=8), A182331 (k=6, h=1), A104118 (k=6, h=5), A104115 (k=6, h=7), A104065 (k=7, h=4), this sequence (k=7, h=6), A144360 (k=8, h=7), A145440 (k=8, h=9), A228034 (k=9, h=2), A159352 (k=10, h=3), A159031 (k=10, h=7).

Programs

  • Magma
    [a: n in [0..300] | IsPrime(a) where a is  7^n+6];
  • Mathematica
    Select[Table[7^n + 6, {n, 0, 300}], PrimeQ]

Extensions

Corrected cross-references - Robert Price, Aug 01 2017

A228031 Primes of the form 7^n + 10.

Original entry on oeis.org

11, 17, 59, 353, 2411, 117659, 823553, 1977326753, 9387480337647754305659, 3219905755813179726837617, 44567640326363195900190045974568017, 616873509628062366290756156815389726793178417, 30226801971775055948247051683954096612865741953
Offset: 1

Views

Author

Vincenzo Librandi, Aug 11 2013

Keywords

Crossrefs

Cf. A217132 (associated n).
Cf. Primes of the form k^n + h: A092506 (k=2, h=1), A057733 (k=2, h=3), A123250 (k=2, h=5), A104066 (k=2, h=7), A104070 (k=2, h=9), A057735 (k=3, h=2), A102903 (k=3, h=4), A102870 (k=3, h=8), A102907 (k=3, h=10), A290200 (k=4, h=1), A182330 (k=5, h=2), A102910 (k=5, h=8), A182331 (k=6, h=1), A104118 (k=6, h=5), A104115 (k=6, h=7), A104065 (k=7, h=4), this sequence (k=7, h=10), A144360 (k=8, h=7), A145440 (k=8, h=9), A228034 (k=9, h=2), A159352 (k=10, h=3), A159031 (k=10, h=7).

Programs

  • Magma
    [a: n in [0..300] | IsPrime(a) where a is  7^n+10];
  • Mathematica
    Select[Table[7^n + 10, {n, 0, 300}], PrimeQ]

Extensions

Corrected cross-references - Robert Price, Aug 01 2017

A217351 Numbers k such that 6^k + 7 is prime.

Original entry on oeis.org

1, 2, 3, 4, 6, 21, 24, 27, 30, 54, 70, 126, 369, 435, 612, 787, 1275, 2155, 2436, 5734, 6016, 16107, 25786, 34266, 38841, 45834, 46584
Offset: 1

Views

Author

Vincenzo Librandi, Oct 02 2012

Keywords

Crossrefs

Cf. A104115 (associated primes).

Programs

  • Mathematica
    Select[Range[10000], PrimeQ[6^# + 7] &]
  • PARI
    is(n)=ispseudoprime(6^n+7) \\ Charles R Greathouse IV, Jun 13 2017

Extensions

a(20)-a(21) from Bruno Berselli, Oct 04 2012
a(22)-a(23) from Michael S. Branicky, Apr 30 2023
a(24)-a(27) from Michael S. Branicky, Sep 19 2024

A228027 Primes of the form 4^k + 9.

Original entry on oeis.org

13, 73, 1033, 262153, 1073741833, 73786976294838206473, 4835703278458516698824713
Offset: 1

Views

Author

Vincenzo Librandi, Aug 11 2013

Keywords

Comments

Subsequence of A104070. - Elmo R. Oliveira, Nov 28 2023

Examples

			262153 is a term because 4^9 + 9 = 262153 is prime.
		

Crossrefs

Cf. A000040, A217350 (corresponding k's).
Cf. Primes of the form r^k + h: A092506 (r=2, h=1), A057733 (r=2, h=3), A123250 (r=2, h=5), A104066 (r=2, h=7), A104070 (r=2, h=9), A057735 (r=3, h=2), A102903 (r=3, h=4), A102870 (r=3, h=8), A102907 (r=3, h=10), A290200 (r=4, h=1), A228026 (r=4, h=3), this sequence (r=4, h=9), A182330 (r=5, h=2), A228029 (r=5, h=6), A102910 (r=5, h=8), A182331 (r=6, h=1), A104118 (r=6, h=5), A104115 (r=6, h=7), A104065 (r=7, h=4), A228030 (r=7, h=6), A228031 (r=7, h=10), A228032 (r=8, h=3), A228033 (r=8, h=5), A144360 (r=8, h=7), A145440 (r=8, h=9), A228034 (r=9, h=2), A159352 (r=10, h=3), A159031 (r=10, h=7).

Programs

  • Magma
    [a: n in [0..200] | IsPrime(a) where a is 4^n+9];
  • Mathematica
    Select[Table[4^n + 9, {n, 0, 200}],PrimeQ]

Formula

a(n) = 4^A217350(n) + 9. - Elmo R. Oliveira, Nov 28 2023

Extensions

Corrected cross-references - Robert Price, Aug 01 2017

A228033 Primes of the form 8^k + 5.

Original entry on oeis.org

13, 2787593149816327892691964784081045188247557, 15177100720513508366558296147058741458143803430094840009779784451085189728165691397
Offset: 1

Views

Author

Vincenzo Librandi, Aug 11 2013

Keywords

Comments

a(4) = 8^64655 + 5 = 1.919...*10^58389 is too large to include. - Amiram Eldar, Jul 23 2025

Crossrefs

Cf. A217355 (associated n).
Cf. Primes of the form k^n + h: A092506 (k=2, h=1), A057733 (k=2, h=3), A123250 (k=2, h=5), A104066 (k=2, h=7), A104070 (k=2, h=9), A057735 (k=3, h=2), A102903 (k=3, h=4), A102870 (k=3, h=8), A102907 (k=3, h=10), A290200 (k=4, h=1), A182330 (k=5, h=2), A102910 (k=5, h=8), A182331 (k=6, h=1), A104118 (k=6, h=5), A104115 (k=6, h=7), A104065 (k=7, h=4), this sequence (k=8, h=5), A144360 (k=8, h=7), A145440 (k=8, h=9), A228034 (k=9, h=2), A159352 (k=10, h=3), A159031 (k=10, h=7).

Programs

  • Magma
    [a: n in [1..300] | IsPrime(a) where a is 8^n+5];
  • Mathematica
    Select[Table[8^n + 5, {n, 4000}], PrimeQ]

A228028 Primes of the form 5^n + 4.

Original entry on oeis.org

5, 29, 15629, 9765629
Offset: 1

Views

Author

Vincenzo Librandi, Aug 11 2013

Keywords

Crossrefs

Cf. A124621 (associated n).
Cf. Primes of the form k^n + h: A092506 (k=2, h=1), A057733 (k=2, h=3), A123250 (k=2, h=5), A104066 (k=2, h=7), A104070 (k=2, h=9), A057735 (k=3, h=2), A102903 (k=3, h=4), A102870 (k=3, h=8), A102907 (k=3, h=10), A290200 (k=4, h=1), A228027 (k=4, h=9), A182330 (k=5, h=2), this sequence (k=5, h=4), A228029 (k=5, h=6), A102910 (k=5, h=8), A182331 (k=6, h=1), A104118 (k=6, h=5), A104115 (k=6, h=7), A104065 (k=7, h=4), A228030 (k=7, h=6), A228031 (k=7, h=10), A228032 (k=8, h=3), A228033 (k=8, h=5), A144360 (k=8, h=7), A145440 (k=8, h=9), A228034 (k=9, h=2), A159352 (k=10, h=3), A159031 (k=10, h=7).

Programs

  • Magma
    [a: n in [0..200] | IsPrime(a) where a is  5^n+4];
  • Mathematica
    Select[Table[5^n + 4, {n, 0, 200}], PrimeQ]

Extensions

Corrected cross-references - Robert Price, Aug 01 2017
Showing 1-9 of 9 results.