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%I #5 Mar 31 2012 14:02:29
%S 0,7,91,92,93,94,95,114,115,116,117,118,4207,4209,4211,4214,4216,4299,
%T 4301,4303,4305,4307,1228,1229,1230,1231,1232,1233,1234,1235,1236,
%U 1237,1238,1239,1240,1241,1242,1243,1244,1245,1246,1247,1248,1249,1250,1347
%N a(n) gives the A089840-index of the nonrecursive Catalan automorphism which is formed from A089840[n] by applying it to the left subtree of a binary tree and leaving the right-hand side subtree intact.
%C If the count of fixed points of the automorphism A089840[n] is given by sequence f, then the count of fixed points of the automorphism A089840[A123694(n)] is given by CONV(f,A000108) (where CONV stands for convolution). See also the comments at A122200.
%H A. Karttunen, <a href="/A089839/a089839.c.txt">C-program for computing the initial terms of this sequence</a>
%H A. Karttunen, <a href="/A089840/a089840p.txt">Prolog-program which illustrates the nonrecursive Catalan automorphisms given on example-lines.</a>
%e When A089840[1] = A069770 (swap binary tree sides) is applied to the left subtree of a binary tree, we get A089840[7] = A089854, thus a(1)=7. When A089840[12] = A074679 is applied to the left subtree of a binary tree, we get A089840[4207] = A089865, thus a(12)=4207.
%K nonn
%O 0,2
%A _Antti Karttunen_, Oct 11 2006
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