A046203 - OEIS

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

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

REFERENCES

L. Comtet, Advanced Combinatorics, Reidel, 1974, p. 83, Problem 25.

LINKS

Table of n, a(n) for n=1..58.

EXAMPLE

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; ...

CROSSREFS

Cf. A003506.

Sequence in context: A278226 A190940 A336869 * A321451 A285943 A100495