%I A095236
%S A095236 1,2,4,8,16,36,136,216,672,2592,10656,35904,167808,426240,1866240,
%T A095236 15287040,35573760,147640320,1323970560,3104317440,64865525760,
%U A095236 352235520000,1891946004480,11505792614400
%N A095236 Given a row of n pay-phones, all initially unused, how many ways are 
               there for n people to choose the pay-phones, assuming each always 
               chooses one of the most distant pay-phones from those in use already?.
%C A095236 More precisely: The first person chooses any pay-phone. Thereafter, each 
               person chooses the middle of a largest span of unused phones; but 
               a span of length L at the end of the row is taken to have length 
               2L-1 and its "middle" is the outermost phone. If a span has even 
               length, either middle may be chosen.
%C A095236 Each person continues to use his pay-phone until all are in use.
%C A095236 The problem was originally stated in terms of urinals in a mens-room.
%H A095236 Leroy Quet, <a href="http://www.prism-of-spirals.net/">Home Page</a> 
               (listed in lieu of email address)
%e A095236 From 6 pay-phones: A may pick any of the 6; he picks #4. B must pick 
               #1. C must pick #6, since the others all are adjacent to A or B. 
               D may pick #2 or #3; he picks #2. E may pick #3 or #5; he picks #5. 
               F must pick #3. That gives the permutation (4,1,6,2,5,3), one of 
               36 possible permutations.
%Y A095236 Cf. A095239, A095240, A095923.
%Y A095236 Sequence in context: A034342 A034343 A002876 this_sequence A018536 A162428 
               A028497
%Y A095236 Adjacent sequences: A095233 A095234 A095235 this_sequence A095237 A095238 
               A095239
%K A095236 nonn
%O A095236 1,2
%A A095236 Leroy Quet Jul 03 2004
%E A095236 Edited by Don Reble (djr(AT)nk.ca), Jul 04 2004