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%I #3 Mar 30 2012 18:50:30
%S 1,2,2,3,1,3,4,3,3,4,5,12,3,12,5,6,60,4,4,60,6,7,20,30,2,30,20,7,8,
%T 140,60,15,15,60,140,8,9,280,105,60,15,60,105,280,9,10,2520,840,140,
%U 12,12,140,840,2520,10,11,2520,252,168,210,6,210,168,252,2520,11,12,27720
%N Denominators of triangular array: T(n,1)=T(n,n)=1/n and T(n,k)=T(n-1,k-1)+t(n-1,k), 1<k<n.
%e Triangle begins:.................Denominators:
%e .............1/1.........................1
%e ..........1/2...1/2....................2...2
%e .......1/3...1/1...1/3...............3...1...3
%e ....1/4...4/3...4/3...1/4..........4...3...3...4
%e .1/5..19/12..8/3..19/12..1/5.....5..12...8..12...5.
%Y Cf. A007318, A080044.
%K nonn,tabl,frac
%O 1,2
%A _Reinhard Zumkeller_, Jan 21 2003