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 11-17 of 17 results.

A295532 Positive integers n such that 13^n == 8 (mod n).

Original entry on oeis.org

1, 5, 371285, 3957661, 70348567451, 42831939409247
Offset: 1

Views

Author

Max Alekseyev, Nov 23 2017

Keywords

Comments

No other terms below 10^15.

Crossrefs

Sequences 13^n == k (mod n): A116621 (k=1), A116622 (k=2), A116629 (k=3), A116630 (k=4), A116611 (k=5), A116631 (k=6), A116632 (k=7), this sequence (k=8), A116636 (k=9), A116620 (k=10), A116638 (k=11), A116639 (k=15).

Programs

  • Mathematica
    Join[{1, 5}, Select[Range[4000000], PowerMod[13, #, #] == 8 &]] (* Robert Price, Apr 10 2020 *)

A277401 Positive integers n such that 7^n == 2 (mod n).

Original entry on oeis.org

1, 5, 143, 1133, 2171, 8567, 16805, 208091, 1887043, 517295383, 878436591673
Offset: 1

Views

Author

Seiichi Manyama, Oct 13 2016

Keywords

Comments

All terms are odd.
No other terms below 10^15. Some larger terms: 181204957971619289, 21305718571846184078167, 157*(7^157-2)/1355 (132 digits). - Max Alekseyev, Oct 18 2016

Examples

			7 == 2 mod 1, so 1 is a term;
16807 == 2 mod 5, so 5 is a term.
		

Crossrefs

Cf. A066438.
Cf. Solutions to 7^n == k (mod n): A277371 (k=-3), A277370 (k=-2), A015954 (k=-1), A067947 (k=1), this sequence (k=2), A277554 (k=3).
Cf. Solutions to b^n == 2 (mod n): A015919 (b=2), A276671 (b=3), A130421 (b=4), A124246 (b=5), this sequence (b=7), A116622 (b=13).

Programs

  • Mathematica
    Join[{1},Select[Range[5173*10^5],PowerMod[7,#,#]==2&]] (* The program will generate the first 10 terms of the sequence; it would take a very long time to generate the 11th term. *) (* Harvey P. Dale, Apr 15 2020 *)
  • PARI
    isok(n) = Mod(7, n)^n == 2; \\ Michel Marcus, Oct 13 2016

Formula

A066438(a(n)) = 2 for n > 1.

Extensions

a(10) from Michel Marcus, Oct 13 2016
a(11) from Max Alekseyev, Oct 18 2016

A333269 Positive integers n such that 17^n == 2 (mod n).

Original entry on oeis.org

1, 3, 5, 3585, 4911, 5709, 1688565, 7361691, 16747709, 3226850283899, 8814126944005, 33226030397603
Offset: 1

Views

Author

Seiichi Manyama, Mar 14 2020

Keywords

Comments

No other terms below 10^16. Some larger term: 95549099691107109423357503242294996525424418266995858732192019626694044445113. - Max Alekseyev, Jan 09 2025

Crossrefs

Cf. Solutions to b^n == 2 (mod n): A015919 (b=2), A276671 (b=3), A130421 (b=4), A124246 (b=5), A277401 (b=7), A116622 (b=13), this sequence (b=17).

Programs

  • PARI
    for(k=1, 1e6, if(Mod(17, k)^k==2, print1(k", ")))
    
  • Python
    A333269_list = [n for n in range(1,10**6) if n == 1 or pow(17,n,n) == 2] # Chai Wah Wu, Mar 14 2020

Extensions

a(10)-a(12) from Max Alekseyev, Jan 09 2025

A321364 Positive integers m such that 13^m == 12 (mod m).

Original entry on oeis.org

1, 13757837, 6969969233, 514208575135
Offset: 1

Views

Author

Max Alekseyev, Nov 07 2018

Keywords

Comments

No other terms below 10^15.
Some larger terms: 14551705803598782884189, 268766423508299769671017810348321281664525668552158231.

Crossrefs

Solutions to 13^m == k (mod m): A001022 (k=0), A015963 (k=-1), A116621 (k=1), A116622 (k=2), A116629 (k=3), A116630 (k=4), A116611 (k=5), A116631 (k=6), A116632 (k=7), A295532 (k=8), A116636 (k=9), A116620(k=10), A116638 (k=11), this sequence (k=12), A321365 (k=14), A116639 (k=15).

Programs

A321365 Positive integers n such that 13^n == 14 (mod n).

Original entry on oeis.org

1, 5805311, 392908759, 399614833907, 2674764845549, 21997277871211, 67146783889057
Offset: 1

Views

Author

Max Alekseyev, Nov 08 2018

Keywords

Comments

No other terms below 10^15.

Crossrefs

Solutions to 13^n == k (mod n): A001022 (k=0), A015963 (k=-1), A116621 (k=1), A116622 (k=2), A116629 (k=3), A116630 (k=4), A116611 (k=5), A116631 (k=6), A116632 (k=7), A295532 (k=8), A116636 (k=9), A116620(k=10), A116638 (k=11), A321364 (k=12), this sequence (k=14), A116639 (k=15).

Programs

A333134 Positive integers k such that 11^k == 2 (mod k).

Original entry on oeis.org

1, 3, 413, 1329, 6587, 11629, 75761, 925071199, 9031140861789, 114876097917387, 1314252479257933
Offset: 1

Views

Author

Seiichi Manyama, Mar 20 2020

Keywords

Comments

No other terms below 10^16. Some larger terms: 1584680529929001639, 15598123298097725094806152851164088027801112472240274433891889912569153113. - Max Alekseyev, Jan 07 2025

Crossrefs

Solutions to b^n == 2 (mod n): A015919 (b=2), A276671 (b=3), A130421 (b=4), A124246 (b=5), A277401 (b=7), this sequence (b=11), A116622 (b=13), A333269 (b=17).
Cf. A015960.

Programs

  • PARI
    for(k=1, 1e6, if(Mod(11, k)^k==2, print1(k", ")))

Extensions

a(9)-a(11) from Max Alekseyev, Jan 07 2025

A333413 Positive integers k such that k divides 13^k + 2.

Original entry on oeis.org

1, 3, 5, 185, 2199, 14061, 5672119, 6719547, 192178873, 913591893, 4589621727, 9762178659, 1157052555699
Offset: 1

Views

Author

Seiichi Manyama, Mar 20 2020

Keywords

Comments

a(14) > 6*10^12. - Giovanni Resta, Mar 29 2020

Crossrefs

Solutions to 13^k == m (mod k): this sequence (m = -2), A015963 (m = -1), A116621 (m = 1), A116622 (m = 2), A116629 (m = 3), A116630 (m = 4), A116611 (m = 5), A116631 (m = 6), A116632 (m = 7), A295532 (m = 8), A116636 (m = 9), A116620 (m = 10), A116638 (m = 11), A116639 (k = 15).
Solutions to b^k == -2 (mod k): A015973 (b = 3), A123062 (b = 5), A277370 (b = 7), this sequence (b = 13), A333414 (b = 17).

Programs

  • Mathematica
    Select[Range[100000], Divisible[PowerMod[13, #, #] + 2, #] &] (* Jinyuan Wang, Mar 28 2020 *)
  • PARI
    for(k=1, 1e6, if(Mod(13, k)^k==-2, print1(k", ")))

Extensions

a(13) from Giovanni Resta, Mar 29 2020
Previous Showing 11-17 of 17 results.