Topswops (2): start by shuffling n cards labeled 1..n. If top card is m, reverse order of top m cards. Repeat until 1 gets to top, then stop. Suppose the whole deck is now sorted (if not, discard this case). a(n) is the maximal number of steps before 1 got to the top.
0, 1, 2, 4, 7, 10, 16, 22, 30, 38, 51, 63, 80, 101, 112, 130, 159, 191, 207, 23
1 seqfan posts
Fri Oct 29 05:35:16 CEST 2010 [seqfan] Implementing first 500 sequences in Java