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%I #5 Nov 04 2013 13:01:50
%S 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,32,
%T 531441,128,256,512,30,31,32,128,81,5832000,729,30840979456,191102976,
%U 102372436321763328,40,41,42,531441,256,1024,531441,531441,5832000,8470728,50,51,32,125,625
%N a(n) = high point in trajectory of n under repeated application of powertrain map (see A133500).
%H N. J. A. Sloane, <a href="/A135381/b135381.txt">Table of n, a(n) for n = 0..10000</a>
%e The trajectory of 39 is 39 -> 19683 -> 5038848 -> 214990848 -> 17179869184 -> 1735247072139264 -> 19999187712 -> 102372436321763328 -> 8813365017182208 -> 0, so a(39) = 102372436321763328.
%p maxtraj := proc(n) local h,p,M,t1,t2,i; M:=100; t1:=n; h:=n; for i from 1 to M do t2:=powertrain(t1); if t2 = t1 then RETURN(n,h); fi; if t2 > t1 then h:=t2; fi; t1:=t2; od; RETURN(n,-1); end;
%Y Cf. A133500, A133501. For records see A135382, A135383.
%K nonn,base
%O 0,3
%A _J. H. Conway_ and _N. J. A. Sloane_, Dec 10 2007
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