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%I #7 Feb 08 2022 20:04:58
%S 1,1,1,1,1,2,4,4,1,1,3,9,18,21,9,1,1,4,16,48,102,132,76,16,1,1,5,25,
%T 100,310,690,970,680,205,25,1,1,6,36,180,735,2340,5420,8160,2550,456,
%U 36,1,1,7,49,294,1491,6195,20195,48440,778315,70245,32571,7602,889,49,1
%N Triangle read by rows, X^n * [1,0,0,0,...]; where X = a tridiagonal matrix with (1,1,1,...) in the main and subsubdiagonals and (1,2,3,...) in the subdiagonal.
%e First few rows of the triangle:
%e 1;
%e 1, 1, 1;
%e 1, 2, 4, 4, 1;
%e 1, 3, 9, 18, 21, 9, 1;
%e 1, 4, 16, 48, 102, 132, 76, 16, 1;
%e 1, 5, 25, 100, 310, 690, 970, 680, 205, 25, 1;
%e 1, 6, 36, 180, 735, 2340, 5420, 8160, 2550, 456, 36, 1;
%e 1, 7, 49, 294, 1491, 6195, 20195, 48440, 77315, 70245, 32571, 7602, 889, 49, 1;
%e ...
%Y Cf. A140733, A140735.
%K nonn,tabl
%O 1,6
%A _Gary W. Adamson_ & _Roger L. Bagula_, May 25 2008