%I A078941
%S A078941 1,4,6,8,10,12,14,15,17,18
%N A078941 Flipping burnt pancakes. Maximum number of spatula flips to sort a stack 
               of n pancakes of different sizes, each burnt on one side, so that 
               the smallest ends up on top, ..., the largest at the bottom and each 
               has its burnt side down.
%C A078941 In a 'spatula flip', a spatula is inserted below any pancake and all 
               pancakes above the spatula are lifted and replaced in reverse order.
%C A078941 It is conjectured that the initial configuration in which the pancakes 
               are in the correct order but all of the burnt sides are up is a worst 
               case for the problem. If so, then this sequence is identical to A078942.
%D A078941 David S. Cohen and Manuel Blum, "On the problem of sorting burnt pancakes", 
               Discrete Applied Math., 61 (1995) 105-120.
%F A078941 a(n) >= A078942(n). a(n+1) <= a(n) + 2. 3n/2 <= a(n) <= 2n-2, where the 
               upper bound holds for n>=10.
%Y A078941 Cf. A078942. A058986 treats the unburnt case.
%Y A078941 Sequence in context: A063287 A134331 A090334 this_sequence A078942 A039767 
               A054023
%Y A078941 Adjacent sequences: A078938 A078939 A078940 this_sequence A078942 A078943 
               A078944
%K A078941 nonn,more
%O A078941 1,2
%A A078941 Dean Hickerson (dean.hickerson(AT)yahoo.com), Dec 18 2002