%I A143796
%S A143796 1,2,2,3,3,3,4,4,5,5,5,5,7,13,13,6,6,9,29,65533,65533,7,7,11,61
%N A143796 Ackermann function, defined recursively by A(0,n) = n+1, A(m+1,0) = A(m,
               1), A(m+1,n+1) = A(m,A(m+1,n)) for any nonnegative integers n, m. 
               Table read by antidiagonals, the second term being A(0,1).
%C A143796 Also known as Ackermann-Peter function.
%C A143796 The next term is 2^65536-3.
%C A143796 This is a computable function that is not primitive recursive.
%D A143796 W. Ackermann, Zum Hilbertschen Aufbau der reellen Zahlen, Math. Ann. 
               99 (1928), 118-133.
%D A143796 R. C. Buck, Mathematical induction and recursive definitions, Amer. Math. 
               Monthly, 70 (1963), 128-135.
%D A143796 R. Peter, Rekursive Funktionen in der Komputer-Theorie. Budapest: Akad. 
               Kiado, 1951.
%H A143796 Wikipedia, <a href="http://en.wikipedia.org/wiki/Ackermann_function">
               Ackermann function</a>.
%H A143796 E. Weisstein, Mathworld, <a href="http://mathworld.wolfram.com/AckermannFunction.html">
               Ackermann function</a>.
%F A143796 A(1,n) = 2+(n+3) - 3 = n + 2.
%F A143796 A(2,n) = 2*(n+3) - 3 = 2n + 3.
%F A143796 A(3,n) = 2^(n+3) - 3.
%F A143796 A(4,n) = 2^^(n+3)- 3 (a power tower of n+3 two's).
%Y A143796 A046859(n)=A(n, n), A126333(n)=A(n, 0). Cf. A143797.
%Y A143796 Sequence in context: A107347 A163127 A077113 this_sequence A057362 A085269 
               A054071
%Y A143796 Adjacent sequences: A143793 A143794 A143795 this_sequence A143797 A143798 
               A143799
%K A143796 nonn,tabl
%O A143796 0,2
%A A143796 Benoit Jubin (benoit_jubin(AT)yahoo.fr), Sep 01 2008