%I A078942
%S A078942 1,4,6,8,10,12,14,15,17,18,19,21,22,23,24,26,28,29
%N A078942 Flipping burnt pancakes. Given a sorted stack of n burnt pancakes of 
               different sizes (smallest on top, ..., largest at the bottom), each 
               with its burnt side up, a(n) is the number of spatula flips needed 
               to restore them to their initial order but with the burnt sides down.
%C A078942 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 A078942 It is conjectured that this initial configuration is a worst case for 
               the general problem of sorting burnt pancakes. If so, then this sequence 
               is identical to A078941.
%D A078942 David S. Cohen and Manuel Blum, "On the problem of sorting burnt pancakes", 
               Discrete Applied Math., 61 (1995) 105-120.
%F A078942 a(n) <= A078941(n). a(n+1) <= a(n) + 2. 3n/2 <= a(n) <= 47n/30 + c for 
               some constant c.
%Y A078942 Cf. A078941, A058986.
%Y A078942 Sequence in context: A134331 A090334 A078941 this_sequence A039767 A054023 
               A032583
%Y A078942 Adjacent sequences: A078939 A078940 A078941 this_sequence A078943 A078944 
               A078945
%K A078942 nonn,more
%O A078942 1,2
%A A078942 Dean Hickerson (dean.hickerson(AT)yahoo.com), Dec 18 2002