On Sat, 21 Feb 2009, wouter meeussen wrote: > > Table[Count[Map[cbs, ListGraphs[n]], False], {n,7}] > {0, 0, 1, 3, 16, 96, 812} Here's what I get with two more terms: A000271 0, 0, 1, 3, 16, 96, 812, 10957, 260494 and for A157015 I get get: 1, 2, 3, 8, 18, 60, 232, 1389, 14174 These of course add up to A000088. ---Edwin