OFFSET
1,2
MATHEMATICA
M = N[Abs[MatrixPower[{{0, 1, 1, 1}, {1, 0, 1, 1}, {1, 1, 0, 1}, {1, 1, 1, 0}}, 1/2]]]
v[1] = {0, 1, 2, 3}
v[n_] := v[n] = M.v[n - 1]
Table[Floor[v[n][[1]]], {n, 1, 50}]
CROSSREFS
KEYWORD
nonn,uned,easy,less
AUTHOR
Roger L. Bagula, Aug 30 2006
STATUS
approved