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Distinct numbers in the triangle of denominators in Leibniz's Harmonic Triangle.
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%I #16 May 11 2015 17:38:40

%S 1,2,3,6,4,12,5,20,30,60,7,42,105,140,8,56,168,280,9,72,252,504,630,

%T 10,90,360,840,1260,11,110,495,1320,2310,2772,132,660,1980,3960,5544,

%U 13,156,858,2860,6435,10296,12012,14,182,1092,4004,10010,18018,24024,15

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

%C 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

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

%H Ivan Neretin, <a href="/A046202/b046202.txt">Table of n, a(n) for n = 1..10000</a>

%e 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; ...

%t 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 *)

%Y Cf. A003506, A046201, A014631.

%K tabf,nonn,easy

%O 1,2

%A _Mohammad K. Azarian_

%E More terms from _James A. Sellers_, Dec 13 1999