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Search: id:A127524
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%I A127524
%S A127524 1,1,2,3,5,6,11,12,20,25,42,43,81,82,150,192,287,288,563,564,982,1277,
%T A127524 2182,2183,3658,3785,7108,8659,13101,13102,27827,27828,47768,61025,
%U A127524 102355,105689,170882,170883,329651,421547,606283,606284,1193038
%N A127524 Number of unordered rooted trees where each subtree from given node has 
               the same number of nodes.
%F A127524 a(1) = 1; a(n+1) = sum_{d|n} C(a(n/d) + d-1, d).
%e A127524 The tree shown below left counts, because the subtree shown on the left 
               has 3 nodes and so does the one on the right and a similar condition 
               holds for the subtrees. The tree shown on the right is not counted, 
               because the subtree shown on the left has 3 nodes, while the one 
               on the right has 4.
%e A127524 O..........O...O...O
%e A127524 |..........|....\./.
%e A127524 O...O...O..O.....O..
%e A127524 .\...\./....\....|..
%e A127524 .O...O......O...O..
%e A127524 ..\./........\./...
%e A127524 ...O..........O....
%Y A127524 Cf. A000081, A127525.
%Y A127524 Sequence in context: A164523 A033159 A083710 this_sequence A117086 A081026 
               A137808
%Y A127524 Adjacent sequences: A127521 A127522 A127523 this_sequence A127525 A127526 
               A127527
%K A127524 nonn
%O A127524 1,3
%A A127524 Franklin T. Adams-Watters (FrankTAW(AT)Netscape.net), Jan 17 2007

    
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Last modified November 27 22:38 EST 2009. Contains 167602 sequences.


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