15 Oct
2010
15 Oct
'10
1:54 p.m.
I don't believe that the following sequence is in OEIS. The (least) number of moves needed to swap n pairs of knights on a 3 by n chessboard. I.e., the number of chess knight moves needed to get from S S S ... S s s s ... s - - - - to - - - - s s s ... s S S S S where s, S are chess knights of opposite colors. Not possible for n = 1, 2, 3. n = 4: 32 moves are necessary and sufficient. n = 5, 6, 7, ... are Rikki-Tikki-Tavi questions on p.250 (R187) of The Inquisitive Problem Solver. R.