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%I #17 Apr 03 2017 04:13:14
%S 0,1,1,1,1,1,2,1,4,1,1,7,3,1,11,10,1,1,17,25,4,1,25,61,18,1,1,36,132,
%T 61,5,1,50,277,194,28,1,1,70,554,553,117,6,1,94,1077,1495,451,40,1,1,
%U 127,2034,3823,1552,197,7,1,168,3770,9427,5020,879,54,1,1,222,6853,22466,15289,3485,305,8,1
%N Irregular triangle read by rows: T(n,k) = number of trees on n nodes with radius k, n>=1, 1 <= k <= floor(n/2).
%C The radius of a tree is the maximal distance of a node from the center.
%H Peter Steinbach, <a href="/A000055/a000055_8.pdf">Field Guide to Simple Graphs, Volume 3</a>, Part 8 (For Volumes 1, 2, 3, 4 of this book see A000088, A008406, A000055, A000664, respectively.)
%F T(n,k) = A034853(n,2k-1) + A034853(n,2k). - _R. J. Mathar_, Apr 03 2017
%e Triangle begins:
%e 0,
%e 1,
%e 1,
%e 1, 1,
%e 1, 2,
%e 1, 4, 1,
%e 1, 7, 3,
%e 1, 11, 10, 1,
%e 1, 17, 25, 4,
%e 1, 25, 61, 18, 1,
%e 1, 36, 132, 61, 5,
%e 1, 50, 277, 194, 28, 1,
%e ...
%Y Cf. A283827.
%Y See also A000676, A000677, A027416, A102911, A004250 (column 2?), A000055 (row sums).
%K nonn,tabf
%O 1,7
%A _N. J. A. Sloane_, Mar 19 2017
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