A046202 Distinct numbers in the triangle of denominators in Leibniz's Harmonic Triangle.

1, 2, 3, 6, 4, 12, 5, 20, 30, 60, 7, 42, 105, 140, 8, 56, 168, 280, 9, 72, 252, 504, 630, 10, 90, 360, 840, 1260, 11, 110, 495, 1320, 2310, 2772, 132, 660, 1980, 3960, 5544, 13, 156, 858, 2860, 6435, 10296, 12012, 14, 182, 1092, 4004, 10010, 18018, 24024, 15

Offset

1,2

Comments

Numbers in the order in which they appear in Leibniz's Harmonic Triangle (A003506). This sequence is a permutation of the natural numbers. - Robert G. Wilson v, Jun 12 2014

References

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

Links

Ivan Neretin, Table of n, a(n) for n = 1..10000

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; ...

Mathematica

t[n_, k_] := Denominator[n!*k!/(n + k + 1)!]; DeleteDuplicates@ Flatten@ Table[t[n - k, k], {n, 0, 14}, {k, 0, n/2}] (* Robert G. Wilson v, Jun 12 2014 *)

Crossrefs

Cf. A003506, A046201, A014631.

Sequence in context: A246429 A305325 A302848 * A372127 A372031 A225642

Adjacent sequences: A046199 A046200 A046201 * A046203 A046204 A046205

Keyword

tabf,nonn,easy

Author

Mohammad K. Azarian

Extensions

More terms from James A. Sellers, Dec 13 1999

Status

approved