A046205 In Leibniz's Harmonic Triangle, write numerator first and then denominator of each element.
1, 1, 1, 2, 1, 2, 1, 3, 1, 6, 1, 3, 1, 4, 1, 12, 1, 12, 1, 4, 1, 5, 1, 20, 1, 30, 1, 20, 1, 5, 1, 6, 1, 30, 1, 60, 1, 60, 1, 30, 1, 6, 1, 7, 1, 42, 1, 105, 1, 140, 1, 105, 1, 42, 1, 7, 1, 8, 1, 56, 1, 168, 1, 280, 1, 280, 1, 168, 1, 56, 1, 8, 1, 9, 1, 72, 1, 252, 1, 504, 1, 630, 1, 504, 1
Offset: 1
Examples
1/1; 1/2, 1/2; 1/3, 1/6, 1/3; 1/4, 1/12, 1/12, 1/4; 1/5, 1/20, 1/30, 1/20, 1/5; ...
References
- L. Comtet, Advanced Combinatorics, Reidel, 1974, p. 83, Problem 25.
Crossrefs
Extensions
More terms from Gregory D Johnson (gjohn(AT)iname.com)
Edited by M. F. Hasler, Apr 05 2015