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 1-2 of 2 results.

A120715 Sequence produced by 14 X 14 Markov chain based on 14-vertex graph formed from direct product of two copies of the graph used in A120714.

Original entry on oeis.org

0, 27, 838, 4025, 29742, 161630, 962784, 5335471, 30120946, 166834881, 926998480, 5122817760, 28316610392, 156260679433, 862162027134, 4754345230927, 26214240435218, 144511100239056, 796592187757696
Offset: 0

Views

Author

Roger L. Bagula, Aug 12 2006, corrected Jul 14 2007

Keywords

Comments

Characteristic polynomial: -17 - 96*x + 65*x^2 + 1528*x^3 + 3840*x^4 + 2996*x^5 - 1566*x^6 - 3312*x^7 - 702*x^8 + 880*x^9 + 372*x^10 - 52*x^11 - 37*x^12 + x^14.

Crossrefs

Cf. A111384.

Programs

  • Magma
    R:=PowerSeriesRing(Integers(), 50); [0] cat Coefficients(R!( x*(27+784*x+1539*x^2-3286*x^3-6475*x^4-1442*x^5-3783*x^6-4444*x^7 -986*x^8)/((1-x-x^2)*(1+3*x+x^2)*(1-5*x-3*x^2+x^3)*(1+x-11*x^2 -17*x^3)) )); // G. C. Greubel, Jul 22 2023
    
  • Mathematica
    M = {{0,1,0,0,0,1,1,1,0,0,0,0,0,0}, {1,0,1,1,0,1,1,0,1,0,0,0,0,0}, {0, 1,0,1,0,0,1,0,0,1,0,0,0,0}, {0,1,1,0,1,1,1,0,0,0,1,0,0,0}, {0,0,0,1, 0,1,1,0,0,0,0,1,0,0}, {1,1,0,1,1,0,1,0,0,0,0,0,1,0}, {1,1,1,1,1,1,0, 0,0,0,0,0,0,1}, {1,0,0,0,0,0,0,0,1,0,0,0,1,1}, {0,1,0,0,0,0,0,1,0,1, 1,0,1,1}, {0,0,1,0,0,0,0,0,1,0,1,0,0,1}, {0,0,0,1,0,0,0,0,1,1,0,1,1, 1}, {0,0,0,0,1,0,0,0,0,0,1,0,1,1}, {0,0,0,0,0,1,0,1,1,0,1,1,0,1}, {0, 0,0,0,0,0,1,1,1,1,1,1,1,0}};
    v[1]= Table[Fibonacci[n], {n,0,13}]; v[n_]:= v[n]= M.v[n-1];
    Table[v[n][[1]], {n,50}]
    LinearRecurrence[{2,30,-6,-263,-250,419,666,228,-28,-17}, {0,27,838, 4025,29742,161630,962784,5335471,30120946,166834881}, 50] (* G. C. Greubel, Jul 22 2023 *)
  • SageMath
    def f(x): return x*(27+784*x+1539*x^2-3286*x^3-6475*x^4-1442*x^5-3783*x^6-4444*x^7 -986*x^8)/((1-x-x^2)*(1+3*x+x^2)*(1-5*x-3*x^2+x^3)*(1+x-11*x^2 -17*x^3))
    def A120715_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( f(x) ).list()
    A120715_list(50) # G. C. Greubel, Jul 22 2023

Formula

G.f.: x*(27 +784*x +1539*x^2 -3286*x^3 -6475*x^4 -1442*x^5 -3783*x^6 -4444*x^7 -986*x^8)/((1 -x -x^2)*(1 +3*x +x^2)*(1 -5*x -3*x^2 +x^3)*(1 +x -11*x^2 -17*x^3)). - Colin Barker, Nov 29 2012

Extensions

Edited by N. J. A. Sloane, Jul 14 2007

A135599 Word obtained from axiom 2 using the morphism 1-> 267, 2-> 13467, 3-> 247, 4-> 23567, 5-> 467, 6-> 12457, 7-> 123456.

Original entry on oeis.org

1, 3, 4, 6, 7, 1, 2, 4, 5, 7, 1, 2, 3, 4, 5, 6, 1, 3, 4, 6, 7, 2, 3, 5, 6, 7, 1, 2, 3, 4, 5, 6, 1, 3, 4, 6, 7, 2, 4, 7, 4, 6, 7, 1, 2, 4, 5, 7, 1, 2, 3, 4, 5, 6, 2, 6, 7, 1, 3, 4, 6, 7, 2, 3, 5, 6, 7, 4, 6, 7, 1, 2, 3, 4, 5, 6, 2, 6, 7, 1, 3, 4, 6, 7, 2, 4, 7, 2, 3, 5, 6, 7, 4, 6, 7, 1, 2, 4, 5, 7, 1, 3, 4, 6, 7
Offset: 1

Views

Author

Roger L. Bagula, Feb 26 2008

Keywords

Comments

Previous name was: Seven-tone substitution on a Fano projective plane graph as used in A120714 (for use in making church tone A,B,C,D,E,F,G music).
Idea inspired by a post in yahoo egroup fractals by "Dahlia Lahla" astro_girl_690(AT)yahoo.ca
In Mathematica you can transfer this to a 12-tone MIDI scale as: to letters
b = a /. 1 -> "a" /. 2 -> "b" /. 3 -> "c" /. 4 -> "d" /. 5 -> "e" /. 6 -> "f" /. 7 -> "g"
back to numbers on a 12-tone scale:
c = b /. "a" -> 1 /. "b" -> 3 /. "c" -> 4 /. "d" -> 6 /. "e" -> 8 /. "f" -> 9 /. "g" -> 11

Crossrefs

Cf. A120714.

Programs

  • Mathematica
    s[1] = {2, 6, 7}; s[2] = {1, 3, 4, 6, 7}; s[3] = {2, 4, 7}; s[4] = {2, 3, 5, 6, 7}; s[5] = {4, 6, 7}; s[6] = {1, 2, 4, 5, 7}; s[7] = {1, 2, 3, 4, 5, 6};
    t[a_] := Flatten[s /@ a];
    p[0] = s[1]; p[1] = t[p[0]]; p[n_] := t[p[n - 1]]; a = p[3]

Extensions

Edited and new name from Joerg Arndt, Sep 26 2018
Showing 1-2 of 2 results.