31 Jul
2006
31 Jul
'06
12:53 p.m.
Franklin T. Adams-Watters asks:
Here are the first 20 terms of a sequence: 1,2,6,12,60,3,21,168,504,2520,27720,4,52,364,5460,21840,371280,1113840,21162960,5
The puzzle is to determine the rule of formation.
An OEIS search for the number 27720 will be enough to give it away, for anyone who's stumped. Well, I think you haven't gone quite far enough to give us the full rule.
From where you left off, I believe the next run-up in your sequence is 5, 105, 2310, 53130, 212520, 1062600, 13813800, 124324200 But is the next thing after that 6 or 7?
--Michael Kleber -- It is very dark and after 2000. If you continue you are likely to be eaten by a bleen.