Leibniz harmonic triangle

The Leibniz harmonic triangle is a triangular arrangement of unit fractions in which the outermost diagonals consist of the reciprocals of the row numbers . The denominators are listed in ( A003506 in the OEIS) while the numerators are all 1s . Just as Pascal's triangle can be computed by using binomial coefficients, so can Leibniz's: L ( r , c ) = 1 r ( n k ) k displaystyle a_n,k=frac 1nbinom nkk where ( n k ) binom nkk is a binomial coefficient .