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 1-4 of 4 results.

A201909 Irregular triangle of 3^k mod prime(n).

Original entry on oeis.org

1, 0, 1, 3, 4, 2, 1, 3, 2, 6, 4, 5, 1, 3, 9, 5, 4, 1, 3, 9, 1, 3, 9, 10, 13, 5, 15, 11, 16, 14, 8, 7, 4, 12, 2, 6, 1, 3, 9, 8, 5, 15, 7, 2, 6, 18, 16, 10, 11, 14, 4, 12, 17, 13, 1, 3, 9, 4, 12, 13, 16, 2, 6, 18, 8, 1, 3, 9, 27, 23, 11, 4, 12, 7, 21, 5, 15
Offset: 1

Views

Author

T. D. Noe, Dec 07 2011

Keywords

Comments

The row lengths are in A062117. Except for the second row, the first term of each row is 1. Many sequences are in this one: starting at A036119 (mod 17) and A070341 (mod 11).

Examples

			The first 9 rows are:
  1
  0
  1, 3, 4,  2
  1, 3, 2,  6,  4,  5
  1, 3, 9,  5,  4
  1, 3, 9
  1, 3, 9, 10, 13,  5, 15, 11, 16, 14,  8,  7,  4, 12, 2,  6
  1, 3, 9,  8,  5, 15,  7,  2,  6, 18, 16, 10, 11, 14, 4, 12, 17, 13
  1, 3, 9,  4, 12, 13, 16,  2,  6, 18,  8
		

Crossrefs

Cf. A062117, A201908 (2^k), A201910 (5^k), A201911 (7^k).
Cf. A070352 (5), A033940 (7), A070341 (11), A168399 (13), A036119 (17), A070342 (19), A070356 (23), A070344 (29), A036123 (31), A070346 (37), A070361 (41), A036126 (43), A070364 (47), A036134 (79), A036136 (89), A036142 (113), A036143 (127), A036145 (137), A036158 (199), A036160 (223).

Programs

  • GAP
    P:=Filtered([1..350],IsPrime);;
    R:=List([1..Length(P)],n->OrderMod(7,P[n]));;
    Flat(Concatenation([1,1,1,2,4,3,0],List([5..10],n->List([0..R[n]-1],k->PowerMod(7,k,P[n]))))); # Muniru A Asiru, Feb 01 2019
  • Mathematica
    nn = 10; p = 3; t = p^Range[0,Prime[nn]]; Flatten[Table[If[Mod[n, p] == 0, {0}, tm = Mod[t, n]; len = Position[tm, 1, 1, 2][[-1,1]]; Take[tm, len-1]], {n, Prime[Range[nn]]}]]

A010691 Period 2: repeat (1,10).

Original entry on oeis.org

1, 10, 1, 10, 1, 10, 1, 10, 1, 10, 1, 10, 1, 10, 1, 10, 1, 10, 1, 10, 1, 10, 1, 10, 1, 10, 1, 10, 1, 10, 1, 10, 1, 10, 1, 10, 1, 10, 1, 10, 1, 10, 1, 10, 1, 10, 1, 10, 1, 10, 1, 10, 1, 10, 1, 10, 1, 10, 1, 10, 1, 10, 1, 10, 1, 10
Offset: 0

Views

Author

Keywords

Comments

Regular continued fraction of (5+sqrt 35)/10. - R. J. Mathar, Nov 21 2011
Sequence is an infinite palindrome in two ways (numbers and English names): ONE, TEN, ONE, TEN, ONE, TEN, ONE, ... . - Eric Angelini, Sep 16 2023

Crossrefs

Programs

  • Magma
    [10^n mod 11: n in [0..80]]; // Vincenzo Librandi, Aug 24 2011
  • Maple
    g:=(1+10*z)/((1-z^2)): gser:=series(g, z=0, 66): seq((coeff(gser, z, n)), n=0..65); # Zerinvary Lajos, Feb 25 2009
  • Mathematica
    PadRight[{},100,{1,10}] (* Harvey P. Dale, Aug 27 2013 *)

Formula

a(n) = -9/2*(-1)^n + 11/2.
G.f.: (1+10*z)/(1-z^2). - Zerinvary Lajos, Feb 25 2009
a(n) = 10^n mod 11. - M. F. Hasler, Mar 10 2011
From Nicolas Bělohoubek, Nov 11 2021: (Start)
a(n) = 10/a(n-1). See also A010695.
a(n) = 11 - a(n-1). See also A010712. (End)

A271350 a(n) = 3^n mod 83.

Original entry on oeis.org

1, 3, 9, 27, 81, 77, 65, 29, 4, 12, 36, 25, 75, 59, 11, 33, 16, 48, 61, 17, 51, 70, 44, 49, 64, 26, 78, 68, 38, 31, 10, 30, 7, 21, 63, 23, 69, 41, 40, 37, 28, 1, 3, 9, 27, 81, 77, 65, 29, 4, 12, 36, 25, 75, 59, 11, 33, 16, 48, 61, 17, 51, 70, 44, 49, 64, 26
Offset: 0

Views

Author

Vincenzo Librandi, Apr 05 2016

Keywords

Crossrefs

Cf. similar sequences of the type 3^n mod p, where p is a prime: A070352 (5), A033940 (7), A070341 (11), A168399 (13), A036119 (17), A070342 (19), A070356 (23), A070344 (29), A036123 (31), A070346 (37), A070361 (41), A036126 (43), A070364 (47), A036134 (79), this sequence (83), A036136 (89), A036142 (113), A036143 (127), A271351 (131), A036145 (137), A036158 (199), A271352 (211), A036160 (223).

Programs

  • Magma
    [Modexp(3, n, 83): n in [0..100]];
    
  • Mathematica
    PowerMod[3, Range[0, 100], 83]
  • PARI
    a(n) = lift(Mod(3, 83)^n); \\ Altug Alkan, Apr 05 2016

Formula

a(n) = a(n-41).

A187466 a(n) = 9^n mod 11.

Original entry on oeis.org

1, 9, 4, 3, 5, 1, 9, 4, 3, 5, 1, 9, 4, 3, 5, 1, 9, 4, 3, 5, 1, 9, 4, 3, 5, 1, 9, 4, 3, 5, 1, 9, 4, 3, 5, 1, 9, 4, 3, 5, 1, 9, 4, 3, 5, 1, 9, 4, 3, 5, 1, 9, 4, 3, 5, 1, 9, 4, 3, 5, 1, 9, 4, 3, 5, 1, 9, 4, 3, 5, 1, 9, 4, 3, 5, 1, 9, 4, 3, 5, 1, 9, 4, 3, 5, 1
Offset: 0

Views

Author

M. F. Hasler, Mar 10 2011

Keywords

Comments

Period 5: repeat [1, 9, 4, 3, 5].

Crossrefs

Programs

Formula

G.f.: (5*x^4 + 3*x^3 + 4*x^2 + 9*x + 1)/(1 - x^5). - Chai Wah Wu, Jun 04 2016
a(n) = a(n-5) for n>4. - Wesley Ivan Hurt, Jun 11 2016
Showing 1-4 of 4 results.