A046203 Even numbers in the triangle of denominators in Leibniz's Harmonic Triangle.
2, 2, 6, 4, 12, 12, 4, 20, 30, 20, 6, 30, 60, 60, 30, 6, 42, 140, 42, 8, 56, 168, 280, 280, 168, 56, 8, 72, 252, 504, 630, 504, 252, 72, 10, 90, 360, 840, 1260, 1260, 840, 360, 90, 10, 110, 1320, 2310, 2772, 2310, 1320, 110, 12, 132, 660, 1980, 3960, 5544, 5544
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
Cf. A003506.
Extensions
More terms from James Sellers, Dec 13 1999