%I
%S 1,5,19,27,87,989,3119,5399,8189,99663,57455,222397,2603047,8476649,
%T 117917347,290190179,360064247,1344262919,3181391639,39179386959,
%U 204692414215,165424388219,2254874520599,2922139183443,594630799853
%N Least count k that deletes the alternate (odd) numbers in the Josephus problem for a circle of numbers 1, 2, 3, ... 2*n, leaving the even numbers undeleted.
%C Arrange 1, 2, 3, ... 2*n clockwise in a circle. Starting the count at 1, delete every kth integer clockwise until exactly half of the numbers have been deleted. a(n) is the least positive integer k for which the deleted numbers are the odd numbers.
%C Deleting the alternate (even) numbers from a circle of 2*n numbers leaving the odd numbers is trivially achieved with k = 2 for all n >= 1.
%H P. Schumer, <a href="http://www.jstor.org/stable/3219179">The Josephus Problem: Once More Around</a>, Mathematics Magazine, Vol. 75:1 (2002), 1217.
%H <a href="/index/J#Josephus">Index entries for sequences related to the Josephus Problem</a>
%Y Cf. A198788, A198789.
%K nonn,more
%O 1,2
%A _William Rex Marshall_, Nov 21 2011
