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Triangle T(n,k) (n >= 1, 0<=k<=n) giving number of preferential arrangements of n things beginning with k (transposed, then read by rows).
1

%I #11 Nov 18 2015 14:13:01

%S 1,1,2,2,5,6,6,18,25,26,24,84,134,149,150,120,480,870,1050,1081,1082,

%T 720,3240,6600,8700,9302,9365,9366,5040,25200,57120,82320,92526,94458,

%U 94585,94586,40320,221760,554400,871920,1038744,1085364,1091414

%N Triangle T(n,k) (n >= 1, 0<=k<=n) giving number of preferential arrangements of n things beginning with k (transposed, then read by rows).

%C Can be generated from Stirling_2 triangle A008277 (cf. A028246, which is intermediate between the two arrays).

%H N. J. A. Sloane and Thomas Wieder, <a href="http://arXiv.org/abs/math.CO/0307064">The Number of Hierarchical Orderings</a>, Order 21 (2004), 83-89.

%e 1;

%e 1, 2;

%e 2, 5, 6;

%e 6, 18, 25, 26; ...

%Y Row sums give A000670. First 3 rows are A000629, A002050 = A000629 - 1, 2*A002051 = (A000629 - 2^m) (m >= 0)

%K nonn,tabl

%O 1,3

%A Eugene McDonnell (Eemcd(AT)aol.com), May 05 2000

%E More terms from _James A. Sellers_, May 05 2000