A323559 Number of rooted self-avoiding knight's paths of length n on an infinite chessboard with first move specified.
1, 7, 49, 337, 2323, 15805, 107737, 727619, 4921655, 33056939, 222323989, 1487064391, 9957971965, 66391431607, 443085643919, 2946553003837, 19611967535129, 130149475953673
Offset: 1