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Bell convolution triangle, T(n,k) = A000110(n-k)*A000110(k)
1

%I #7 Sep 08 2013 19:59:24

%S 1,1,1,2,1,2,5,2,2,5,15,5,4,5,15,52,15,10,10,15,52,203,52,30,25,30,52,

%T 203,877,203,104,75,75,104,203,877,4140,877,406,260,225,260,406,877,

%U 4140,21147,4140,1754,1015,780,780,1015,1754,4140,21147

%N Bell convolution triangle, T(n,k) = A000110(n-k)*A000110(k)

%C Row sums = A014322: (1, 2, 5, 14, 44, 154,...) the Bell numbers convolved with themselves.

%F Triangle read by rows, T(n,k) = A000110(n-k)*A000110(k)

%e First few rows of the triangle =

%e 1;

%e 1, 1;

%e 2, 1, 2;

%e 5, 2, 2, 5;

%e 15, 5, 4, 5, 15;

%e 52, 15, 10, 10, 15, 52;

%e 203, 52, 30, 25, 30, 52, 203;

%e ...

%e Row 3 = (5, 2, 2, 5) = termwise products of (1, 1, 2, 5) and (5, 2, 1, 1) = (5*1, 1*2, 2*1, 5*1).

%Y A000110, Cf. A014322

%K nonn,tabl

%O 0,4

%A _Gary W. Adamson_, Sep 12 2008

%E More terms from _Philippe Deléham_, Jan 29 2012