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.

A015973 Positive integers n such that n | (3^n + 2).

Original entry on oeis.org

1, 5, 77, 278377, 3697489, 219596687717, 56865169816619
Offset: 1

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Author

Keywords

Comments

No other terms below 10^15. Some larger term: 3142423971953435020522506484187. - Max Alekseyev, Aug 04 2011

Crossrefs

Solutions to 3^n == k (mod n): A277340 (k=-11), A277289 (k=-7), A277288 (k=-5), this sequence (k=-2), A015949 (k=-1), A067945 (k=1), A276671 (k=2), A276740 (k=5), A277126 (k=7), A277274 (k=11).

Extensions

a(1)=1 prepended and a(6)-a(7) added by Max Alekseyev, Aug 04 2011

A276740 Numbers n such that 3^n == 5 (mod n).

Original entry on oeis.org

1, 2, 4, 76, 418, 1102, 4687, 7637, 139183, 2543923, 1614895738, 9083990938, 23149317409, 497240757797, 4447730232523, 16000967516764, 65262766108619, 141644055557882
Offset: 1

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Author

Dmitry Ezhov, Sep 16 2016

Keywords

Comments

No other terms below 10^15. Some larger terms: 194995887252090239, 2185052151122686482926861593785262. - Max Alekseyev, Oct 13 2016

Examples

			3 == 5 (mod 1), so 1 is a term;
9 == 5 (mod 2), so 2 is a term.
		

Crossrefs

Cf. A066601.
Solutions to 3^n == k (mod n): A277340 (k=-11), A277289 (k=-7), A277288 (k=-5), A015973 (k=-2), A015949 (k=-1), A067945 (k=1), A276671 (k=2), this sequence (k=5), A277628 (k=6), A277126 (k=7), A277630 (k=8), A277274 (k=11).

Programs

  • Mathematica
    Select[Range[10^7], PowerMod[3, #, #] == Mod[5, #] &] (* Michael De Vlieger, Sep 26 2016 *)
  • PARI
    isok(n) = Mod(3, n)^n == Mod(5, n); \\ Michel Marcus, Sep 17 2016
    
  • Python
    A276740_list = [1,2,4]+[n for n in range(5,10**6) if pow(3,n,n) == 5] # Chai Wah Wu, Oct 04 2016

Extensions

a(11)-a(13) from Chai Wah Wu, Oct 05 2016
a(14) from Lars Blomberg, Oct 12 2016
a(15)-a(18) from Max Alekseyev, Oct 13 2016
a(12) was missing Robert G. Wilson v, Oct 19 2016

A277126 Positive integers n such that 3^n == 7 (mod n).

Original entry on oeis.org

1, 2, 295, 883438, 252027511, 7469046275, 26782373099, 53191768475, 55246802458, 819613658855, 893727887879978
Offset: 1

Views

Author

Seiichi Manyama, Oct 06 2016

Keywords

Comments

No other terms below 10^15. A larger term: 9135884036634915191945452485106476242. - Max Alekseyev, Oct 12 2016
Terms are not divisible by 127 (Alekseyev 2016).

Examples

			3 == 7 mod 1, so 1 is a term;
9 == 7 mod 2, so 2 is a term.
		

References

  • M. A. Alekseyev. "Problem 4101". Crux Mathematicorum 42:1 (2016), 28.

Crossrefs

Solutions to 3^n == k (mod n): A277340 (k=-11), A277289 (k=-7), A277288 (k=-5), A015973 (k=-2), A015949 (k=-1), A067945 (k=1), A276671 (k=2), A276740 (k=5), this sequence (k=7), A277274 (k=11).

Programs

Extensions

a(5) from Joerg Arndt, Oct 06 2016
a(6)-a(11) from Max Alekseyev, Oct 12 2016

A277289 Positive integers n such that n | (3^n + 7).

Original entry on oeis.org

1, 2, 4, 5, 8, 25, 44, 4664, 6568, 1353025, 2919526, 5709589, 7827725, 64661225, 85132756, 153872408, 743947534, 34304296003, 38832409867, 40263727492, 1946603375348, 2469908330348, 64471909888247, 274267749806485, 888906849689897, 896501949422459
Offset: 1

Views

Author

Seiichi Manyama, Oct 09 2016

Keywords

Comments

No other terms below 10^15. - Max Alekseyev, Oct 14 2016
492385451091805616444 is a term.

Examples

			3^25 + 7 = 847288609450 = 25 * 33891544378, so 25 is a term.
		

Crossrefs

Solutions to 3^n == k (mod n): A277340 (k=-11), this sequence (k=-7), A277288 (k=-5), A015973 (k=-2), A015949 (k=-1), A067945 (k=1), A276671 (k=2), A276740 (k=5), A277126 (k=7), A277274 (k=11).

Programs

  • PARI
    is(n)=Mod(3,n)^n==-7; \\ Joerg Arndt, Oct 09 2016
    
  • Python
    A277289_list = [1,2,4,5]+[n for n in range(6,10**6) if pow(3,n,n)==n-7] # Chai Wah Wu, Oct 12 2016

Extensions

a(17) from Joerg Arndt, Oct 09 2016
a(18)-a(20) from Chai Wah Wu, Oct 12 2016
a(21)-a(26) from Max Alekseyev, Oct 14 2016

A277274 Positive integers n such that 3^n == 11 (mod n).

Original entry on oeis.org

1, 2, 1162, 1692934, 3851999, 274422823, 14543645261, 492230729674, 773046873382, 13010754158393, 31446154470014, 583396812890467, 598371102650063
Offset: 1

Views

Author

Seiichi Manyama, Oct 08 2016

Keywords

Comments

No other terms below 10^15. Some larger terms: 38726095838775708310162, 2682806839696008709567739369. - Max Alekseyev, Oct 12 2016

Examples

			3 == 11 mod 1, so 1 is a term.
9 == 11 mod 2, so 2 is a term.
		

Crossrefs

Solutions to 3^n == k (mod n): A277340 (k=-11), A277289 (k=-7), A277288 (k=-5), A015973 (k=-2), A015949 (k=-1), A067945 (k=1), A276671 (k=2), A276740 (k=5), A277126 (k=7), this sequence (k=11).

Programs

  • Mathematica
    k = 3; lst = {1, 2}; While[k < 12000000001, If[ PowerMod[3, k, k] == 11, AppendTo[lst, k]]; k++]; lst (* Robert G. Wilson v, Oct 08 2016 *)

Extensions

a(7)-a(13) from Max Alekseyev, Oct 12 2016

A277340 Positive integers n such that n | (3^n + 11).

Original entry on oeis.org

1, 2, 4, 7, 10, 92, 1099, 29530, 281473, 657892, 3313964, 9816013, 18669155396, 94849225930, 358676424226, 957439868543, 1586504109310, 41431374800470, 241469610359708, 256165266592379
Offset: 1

Views

Author

Seiichi Manyama, Oct 09 2016

Keywords

Comments

No other terms below 10^15. Some larger terms: 9151612250553176993, 1401778935853533028413047652833, 5645122353966835994338815444821661584288016927879134, 313*(3^626+11)/6562567821545333606830 (280 digits). - Max Alekseyev, Oct 14 2016

Examples

			3^10 + 11 = 59060 = 10 * 5906, so 10 is a term.
		

Crossrefs

Solutions to 3^n == k (mod n): this sequence (k=-11), A277289 (k=-7), A277288 (k=-5), A015973 (k=-2), A015949 (k=-1), A067945 (k=1), A276671 (k=2), A276740 (k=5), A277126 (k=7), A277274 (k=11).

Programs

  • PARI
    is(n)=Mod(3,n)^n==-11; \\ Joerg Arndt, Oct 10 2016
    
  • Python
    A277340_list = [1,2,4,7,10]+[n for n in range(11,10**6) if pow(3,n,n)==n-11] # Chai Wah Wu, Oct 11 2016

Extensions

a(13)-a(14) from Chai Wah Wu, Oct 12 2016
a(15)-a(20) from Max Alekseyev, Oct 14 2016

A327943 Numbers m that divide 6^m + 5.

Original entry on oeis.org

1, 11, 341, 186787, 8607491, 9791567, 11703131, 14320387, 50168819, 952168003, 71654478989, 1328490399527
Offset: 1

Views

Author

Juri-Stepan Gerasimov, Sep 30 2019

Keywords

Comments

Conjecture: For k > 1, k^m == 1 - k (mod m) has infinitely many positive solutions.
Also includes 11834972807906571233 = 31*381773316384082943. - Robert Israel, Oct 03 2019
a(13) > 10^15. - Max Alekseyev, Nov 10 2022

Crossrefs

Solutions to k^m == 1-k (mod m): A006521 (k = 2), A015973 (k = 3), A327840 (k = 4), A123047 (k = 5), this sequence (k = 6).

Programs

  • Magma
    [1] cat [n: n in [1..10^8] | Modexp(6, n, n) + 5 eq n];
  • Mathematica
    Join[{1},Select[Range[98*10^5],PowerMod[6,#,#]==#-5&]] (* The program generates the first six terms of the sequence. To generate more, increase the Range constant but the program may take a long time to run. *) (* Harvey P. Dale, Feb 05 2022 *)

Extensions

a(11) from Giovanni Resta, Oct 02 2019
a(12) from Max Alekseyev, Nov 10 2022

A277628 Positive integers n such that 3^n == 6 (mod n).

Original entry on oeis.org

1, 3, 21, 936340943, 10460353197, 9374251222371, 23326283250291, 615790788171551
Offset: 1

Views

Author

Dmitry Ezhov, Oct 24 2016

Keywords

Comments

No other terms below 10^15. - Max Alekseyev, Sep 12 2017

Crossrefs

Solutions to 3^n == k (mod n): A277340 (k=-11), A277289 (k=-7), A277288 (k=-5), A015973 (k=-2), A015949 (k=-1), A067945 (k=1), A276671 (k=2), A276740 (k=5), this sequence (k=6), A277126 (k=7), A277630 (k=8), A277274 (k=11).

Programs

  • PARI
    isok(n) = Mod(3, n)^n == Mod(6, n);

Extensions

a(6)-a(8) from Max Alekseyev, Sep 12 2017

A277630 Positive integers n such that 3^n == 8 (mod n).

Original entry on oeis.org

1, 5, 2352527, 193841707, 17126009179703, 380211619942943
Offset: 1

Views

Author

Dmitry Ezhov, Oct 24 2016

Keywords

Comments

No other terms below 10^15. - Max Alekseyev, Sep 13 2017

Crossrefs

Solutions to 3^n == k (mod n): A277340 (k=-11), A277289 (k=-7), A277288 (k=-5), A015973 (k=-2), A015949 (k=-1), A067945 (k=1), A276671 (k=2), A276740 (k=5), A277628 (k=6), A277126 (k=7), this sequence (k=8), A277274 (k=11).

Programs

  • PARI
    isok(n) = Mod(3, n)^n == Mod(8, n);

Extensions

a(5)-a(6) established by Max Alekseyev, Sep 13 2017
Showing 1-9 of 9 results.