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%I #9 Jul 13 2012 17:34:09
%S 1,2,13,6,50,373,24,246,2210,20533,120,1464,15366,163490,1834933,720,
%T 10200,122424,1466886,18307490,241335733,5040,81360,1098840,14637624,
%U 201050886,2892317090,43830481333,40320,730800,10967760,160766040
%N Array read by antidiagonals: T(m,n) = Sum(1<=i<=m) i * ( n + 2(i-1) )!
%C Index numbers (compare A055089) of permutations like (n,1, n+1,2, n+2,3, ...).
%H Tilman Piesk, <a href="/A211366/b211366.txt">Table of n, a(n) for n = 1..2016</a>
%H Tilman Piesk, <a href="http://en.wikiversity.org/wiki/Inversion_%28discrete_mathematics%29#arrays1">Arrays of permutations</a> (Wikiversity)
%e T(3,2) = Sum( 1 <= i <= 3 ) i * ( 2 + 2(i-1) )!
%e = 1*(2+0)! + 2*(2+2)! + 3*(2+4)!
%e = 1*2 + 2*24 + 3*720
%e = 2210
%o MATLAB code is shown on the Wikiversity page.
%Y Cf. A055089.
%K nonn,tabl
%O 1,2
%A _Tilman Piesk_, Jul 07 2012
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