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 13 results. Next

A058958 Numbers k such that 3^k + 4 is prime.

Original entry on oeis.org

0, 1, 2, 3, 6, 9, 10, 22, 30, 42, 57, 87, 174, 195, 198, 562, 994, 2421, 2487, 4629, 5838, 13698, 14730, 16966, 25851, 98634, 117222, 192819, 226038, 296115, 318465, 355902
Offset: 1

Views

Author

Robert G. Wilson v, Jan 13 2001

Keywords

Comments

Next term > 15000. The primes corresponding to 4629, ..., 14730 pass PARI's ispseudoprime() and the Rabin-Miller test for the first 100 prime bases. - Joerg Arndt, Jul 19 2012
Used PFGW (Fermat and Lucas, BLS) to determine (probable) primality of a(24)-a(26). - Robert Price, Jun 30 2013
a(27) > 10^5. - Robert Price, Jun 30 2013
a(29) > 2*10^5. - Robert Price, Dec 10 2013
a(31) > 3*10^5. - Tyler NeSmith, Dec 10 2020

Crossrefs

Cf. A102903 (corresponding primes).

Programs

  • Magma
    [n: n in [0..700] | IsPrime(3^n+4)]; // Vincenzo Librandi, Aug 25 2015
  • Mathematica
    Do[ If[ PrimeQ[3^n + 4], Print[n] ], {n, 0, 3000} ]
    Select[Range[0,3000],PrimeQ[3^#+4]&] (* Harvey P. Dale, Sep 07 2022 *)
  • PARI
    for(n=0,10^5,if(ispseudoprime(3^n+4),print1(n,", "))); /* Joerg Arndt, Jul 19 2012 */
    

Extensions

Terms 4629 ... 14730 from Joerg Arndt, Jul 19 2012
0 added by Bruno Berselli, Oct 04 2012
a(24)-a(26) from Robert Price, Jun 30 2013
a(27)-a(28) from Robert Price, Dec 10 2013
a(29)-a(30) from Tyler NeSmith, Dec 10 2020
a(31)-a(32) from Aurelien Gibier, Oct 02 2024

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

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

A243437 Primes of the form 3^k + 16.

Original entry on oeis.org

17, 19, 43, 97, 2203, 6577, 19699, 531457, 1594339, 14348923, 7625597485003, 617673396283963, 239299329230617529590099, 1570042899082081611640534579, 42391158275216203514294433217, 608266787713357709119683992618861323
Offset: 1

Views

Author

Vincenzo Librandi, Jun 05 2014

Keywords

Comments

Associated n: 0, 1, 3, 4, 7, 8, 9, 12, 13, 15, 27, 31, 49, 57, 60, 75, 139, 147, ...

Crossrefs

Cf. A000040, A205647 (corresponding k's).
Cf. Similar sequences listed in A102903.

Programs

  • Magma
    [a: n in [0..200] | IsPrime(a) where a is 3^n+16];
  • Mathematica
    Select[Table[3^n + 16, {n, 0, 500}], PrimeQ]

Formula

a(n) = 3^A205647(n) + 16. - Elmo R. Oliveira, Nov 11 2023
Showing 1-10 of 13 results. Next