A137763 Central elements in writing first the denominator and then the numerator(left to right) of Leibniz's harmonic-like triangle.

1, 1, 6, 5, 30, 31, 140, 209, 630, 1471, 2772, 10625

Offset: 1

Author

Mohammad K. Azarian, Feb 13 2008

Keywords

• nonn
• tabf
• frac
• less

Examples

			1/1; --> 1 1
1/2, 1/2; -->
1/3, 5/6, 1/3;  --> 6 5
1/4, 7/12, 7/12, 1/4; --> ...
1/5, 9/20, 31/30, 9/20, 1/5;
		

Crossrefs

Cf. A046201, A046204, A046205, A046206, A046208, A046212, A137752, A137753, A137754, A137755, A137756, A137757, A137758, A137759, A137760, A137761, A137762.

Formula

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