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.

A134326 The sum of the elements in the first, middle and last row of the n-th power of the 9-by-9 matrix defined in the formula.

Original entry on oeis.org

3, 11, 34, 112, 359, 1167, 3764, 12191, 39391, 127434, 411973, 1332290, 4307638, 13928919, 45036841, 145621921, 470842799, 1522389829, 4922341763, 15915370482, 51458800352, 166380151440, 537950254595, 1739329494378
Offset: 0

Views

Author

Roger L. Bagula, Jan 16 2008

Keywords

Comments

The characteristic polynomial is -5 x - 8 x^2 + 42 x^3 + 37 x^4 - 19 x^5 - 23 x^6 + 5 x^7 + 4 x^8 - x^9.
The largest root of the polynomial is 3.23322.
The value of the associated matrix game is zero.

Programs

  • Mathematica
    M = {{0, 1, 0, 1, 0, 0, 1, 0, 0}, {0, 0, 1, 0, 1, 0, 0, 1, 0}, {1, 0, 0, 0, 0, 1, 0, 0, 1}, {1, 0, 0, 0, 1, 0, 1, 0, 0}, {0, 1, 0, 1, 0, 0, 0, 1, 0}, {0, 0, 1, 0, 1, 0, 0, 0, 1}, {1, 0, 0, 1, 0, 0, 1, 1, 0}, {0, 1, 0, 0, 1, 0, 0, 1, 0}, {0, 0, 1, 0, 0, 1, 0, 0, 2}};
    v[0] = {1, 0, 0, 0, 1, 0, 0, 0, 1}; v[n_] := v[n] = M.v[n - 1]; a = Table[Apply[Plus, v[n]], {n, 0, 50}]
    LinearRecurrence[{4,5,-23,-19,37,42,-8,-5},{3,11,34,112,359,1167,3764,12191},30] (* Harvey P. Dale, Mar 06 2022 *)

Formula

M = {{0, 1, 0, 1, 0, 0, 1, 0, 0}, {0, 0, 1, 0, 1, 0, 0, 1, 0}, {1, 0, 0, 0, 0, 1, 0, 0, 1}, {1, 0, 0, 0, 1, 0, 1, 0, 0}, {0, 1, 0, 1, 0, 0, 0, 1, 0}, {0, 0, 1, 0, 1, 0, 0, 0, 1}, {1, 0, 0, 1, 0, 0, 1, 1, 0}, {0, 1, 0, 0, 1, 0, 0, 1, 0}, {0, 0, 1, 0, 0, 1, 0, 0, 2}}; v[0] = {1, 0, 0, 0, 1, 0, 0, 0, 1}; v[n_] := v[n] = M.v[n - 1]; a(n) = Sum[v[n][[i]],{i,1,9}]
a(n)= 4*a(n-1) +5*a(n-2) -23*a(n-3) -19*a(n-4) +37*a(n-5) +42*a(n-6) -8*a(n-7) -5*a(n-8). G.f.: -x*(-3+x+25*x^2+10*x^3-51*x^4-51*x^5+10*x^6+11*x^7) / (1-4*x-5*x^2+23*x^3+ 19*x^4-37*x^5-42*x^6+8*x^7+5*x^8). [From R. J. Mathar, Aug 12 2009]

Extensions

Offset set to zero by the Associate Editors of the OEIS, Sep 11 2009
Linear recurrence index corrected by Harvey P. Dale, Mar 06 2022