OFFSET
1,1
COMMENTS
Becomes cyclic with period 5: {-1, 1, 0, 1, -1} at a(13). - Stefan Steinerberger, Nov 17 2007
LINKS
Index entries for linear recurrences with constant coefficients, signature (-1, -1, -1, -1).
MATHEMATICA
a[1] = a[2] = a[3] = a[4] = 1; a[n_] := a[n] = a[n - 1]*a[n - 4] - a[n - 2]*a[n - 3]; Array[a, 105] (* Robert G. Wilson v, Nov 09 2007 *)
a = {1, 1, 1, 1}; Do[AppendTo[a, a[[ -1]]*a[[ -4]] - a[[ -2]]*a[[ -3]]], {90}]; a (* Stefan Steinerberger, Nov 17 2007 *)
CROSSREFS
KEYWORD
sign,easy
AUTHOR
Ben Branman, Nov 08 2007
EXTENSIONS
More terms from Robert G. Wilson v, Nov 09 2007
STATUS
approved