OFFSET
1,8
COMMENTS
Original name started "Bi_Steinbach heptagon recursion".
LINKS
Index entries for linear recurrences with constant coefficients, signature (3, 1, -7, 1, 3, -1).
FORMULA
O.g.f.: x*(1-x-3*x^2)*(1-x-x^2)/((1-2*x-x^2+x^3)*(1-x-2*x^2+x^3)). - R. J. Mathar, Aug 22 2008
MATHEMATICA
a[0] = 1; a[1] = 1; a[2] = 1; a[3] = 1; a[4] = 1; a[5] = 1; a[n_] := a[n] = -a[n - 6] + 3 a[n - 5] + a[n - 4] - 7 a[n - 3] + a[n - 2] + 3 a[n - 1] Table[a[n], {n, 0, 30}]
M = {{0, 1, 0, 0, 0, 0}, {0, 0, 1, 0, 0, 0}, {0, 0, 0, 1, 0, 0}, {0, 0, 0, 0, 1, 0}, {0, 0, 0, 0, 0, 1}, {-1, 3, 1, -7, 1, 3}} v[1] = {1, 1, 1, 1, 1, 1} v[n_] := v[n] = M.v[n - 1] a = Table[Floor[v[n][[1]]], {n, 1, 50}]
LinearRecurrence[{3, 1, -7, 1, 3, -1}, {1, 1, 1, 1, 1, 1}, 40] (* or *) Rest[ CoefficientList[ Series[x(1-x-3x^2)(1-x-x^2)/((1-2x-x^2+x^3)(1-x-2x^2+x^3)), {x, 0, 40}], x]] (* Harvey P. Dale, Jun 24 2011 *)
CROSSREFS
KEYWORD
sign
AUTHOR
Roger L. Bagula and Gary W. Adamson, Sep 15 2006
STATUS
approved