%I #14 Jun 22 2013 16:06:10
%S 1,1,6,5,30,31,140,209,630,1471,2772,10625
%N Central elements in writing first the denominator and then the numerator(left to right) of Leibniz's harmonic-like triangle.
%F a(2n) = A137762(2n-1); a(2n-1) = A137762(2n) = A046212(2n-1) = A056040(2n-1) = A100071(2n-1). - _M. F. Hasler_, Jan 25 2012
%e 1/1; --> 1 1
%e 1/2, 1/2; -->
%e 1/3, 5/6, 1/3; --> 6 5
%e 1/4, 7/12, 7/12, 1/4; --> ...
%e 1/5, 9/20, 31/30, 9/20, 1/5;
%Y Cf. A046201, A046204, A046205, A046206, A046208, A046212, A137752, A137753, A137754, A137755, A137756, A137757, A137758, A137759, A137760, A137761, A137762.
%K nonn,tabf,frac,less
%O 1,3
%A _Mohammad K. Azarian_, Feb 13 2008