public function dataProviderForPellNumber()
{
return [[-1, []], [0, []], [1, [0]], [2, [0, 1]], [3, [0, 1, 2]], [4, [0, 1, 2, 5]], [5, [0, 1, 2, 5, 12]], [6, [0, 1, 2, 5, 12, 29]], [13, [0, 1, 2, 5, 12, 29, 70, 169, 408, 985, 2378, 5741, 13860]]];
}