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.

A271832 Period 12 zigzag sequence: repeat [0,1,2,3,4,5,6,5,4,3,2,1].

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 6, 5, 4, 3, 2, 1, 0, 1, 2, 3, 4, 5, 6, 5, 4, 3, 2, 1, 0, 1, 2, 3, 4, 5, 6, 5, 4, 3, 2, 1, 0, 1, 2, 3, 4, 5, 6, 5, 4, 3, 2, 1, 0, 1, 2, 3, 4, 5, 6, 5, 4, 3, 2, 1, 0, 1, 2, 3, 4, 5, 6, 5, 4, 3, 2, 1, 0, 1, 2, 3, 4, 5, 6, 5, 4, 3, 2, 1, 0, 1
Offset: 0

Views

Author

Wesley Ivan Hurt, Apr 15 2016

Keywords

Comments

a(n)/36 is the probability that the sum shown after rolling a pair of standard dice is 1+(n mod 12). - Mathew Englander, Jul 11 2022
Decimal expansion of 37037/3000003. - Elmo R. Oliveira, Mar 03 2024

Crossrefs

Period k zigzag sequences: A000035 (k=2), A007877 (k=4), A260686 (k=6), A266313 (k=8), A271751 (k=10), this sequence (k=12), A279313 (k=14), A279319 (k=16), A158289 (k=18).

Programs

  • Magma
    &cat[[0, 1, 2, 3, 4, 5, 6, 5, 4, 3, 2, 1]: n in [0..10]];
    
  • Maple
    A271832:=n->[0, 1, 2, 3, 4, 5, 6, 5, 4, 3, 2, 1][(n mod 12)+1]: seq(A271832(n), n=0..300);
  • Mathematica
    CoefficientList[Series[x*(1 + x + x^2 + x^3 + x^4 + x^5)/(1 - x + x^6 - x^7), {x, 0, 100}], x]
  • PARI
    lista(nn) = for(n=0, nn, print1(abs(n-12*round(n/12)), ", ")); \\ Altug Alkan, Apr 15 2016

Formula

G.f.: x*(1 + x + x^2 + x^3 + x^4 + x^5)/(1 - x + x^6 - x^7).
a(n) = a(n-1) - a(n-6) + a(n-7) for n>6.
a(n) = abs(n - 12*round(n/12)).
a(n) = Sum_{i=1..n} (-1)^floor((i-1)/6).
a(2n) = a(10n) = 2*A260686(n), a(2n+1) = A110551(n).
a(3n) = 3*A007877(n), a(4n) = a(8n) = 4*A011655(n).
a(6n) = A010677(n) = 6*A000035(n).
a(n) = a(n-12) for n >= 12. - Wesley Ivan Hurt, Sep 07 2022

A309315 Number of 5-colorings of an n-wheel graph.

Original entry on oeis.org

60, 120, 420, 1200, 3660, 10920, 32820, 98400, 295260, 885720, 2657220, 7971600, 23914860, 71744520, 215233620, 645700800, 1937102460, 5811307320, 17433922020, 52301766000, 156905298060, 470715894120, 1412147682420, 4236443047200, 12709329141660
Offset: 3

Views

Author

Aalok Sathe, Jul 23 2019

Keywords

Comments

Cf. A010677 (for 3-colorings), A090860 (for 4-colorings).

Crossrefs

Programs

  • PARI
    Vec(60*x^3 / ((1 + x)*(1 - 3*x)) + O(x^30)) \\ Colin Barker, Jul 24 2019

Formula

a(n) = 5*3^(n-1)-15*(-1)^n.
From Colin Barker, Jul 24 2019: (Start)
G.f.: 60*x^3 / ((1 + x)*(1 - 3*x)).
a(n) = 2*a(n-1) + 3*a(n-2) for n>4.
(End)

A360222 a(n) is the number of permutable pieces in a standard n X n X n Rubik's cube.

Original entry on oeis.org

0, 8, 20, 56, 92, 152, 212, 296, 380, 488, 596, 728, 860, 1016, 1172, 1352, 1532, 1736, 1940, 2168, 2396, 2648, 2900, 3176, 3452, 3752, 4052, 4376, 4700, 5048, 5396, 5768, 6140, 6536, 6932, 7352, 7772, 8216, 8660, 9128, 9596, 10088, 10580, 11096, 11612, 12152
Offset: 1

Views

Author

William Riley Barker, Jan 30 2023

Keywords

Examples

			The 2 X 2 X 2 Rubik's cube consists of 8 corner pieces, so a(2) = 8; the 3 X 3 X 3 cube has 8 corner pieces, 12 edge pieces, and 6 non-permutable center pieces, so a(3) = 8 + 12 = 20.
		

Crossrefs

Programs

  • Mathematica
    A360222[n_] := If[n == 1, 0, 6*((n-2)*n - Mod[n, 2]) + 8]; Array[A360222, 50] (* or *)
    LinearRecurrence[{2, 0, -2, 1}, {0, 8, 20, 56, 92}, 50] (* Paolo Xausa, Oct 04 2024 *)
  • Python
    N = 20
    seq = [0]
    for n in range(2, N+1):
       seq.append( 8 + 12*(n-2) + 6*((n-2)**2 - (n%2)) )

Formula

a(n) = 8 + 12*(n-2) + 6*((n-2)^2 - (n mod 2)) for n > 1, a(1) = 0.
G.f.: 4*x^2*(x^3-4*x^2-x-2)/((x+1)*(x-1)^3).
a(n) = A005897(n-1) - A010677(n) for n>=2.
E.g.f.: 2*(2*(x - 2) + (3*x^2 - 3*x + 4)*cosh(x) + (3*x^2 - 3*x + 1)*sinh(x)). - Stefano Spezia, Feb 02 2023

A021169 Decimal expansion of 1/165.

Original entry on oeis.org

0, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6, 0, 6
Offset: 0

Views

Author

Keywords

Crossrefs

Cf. A010677 shifted right.

Programs

  • Mathematica
    Join[{0,0},RealDigits[1/165,10,120][[1]]] (* or *) PadRight[{0},120,{6,0}] (* Harvey P. Dale, Aug 29 2021 *)
Showing 1-4 of 4 results.