%I A007622 M4096
%S A007622 6,12,20,30,42,56,60,72,90,105,110,132,140,156,168,182,210,240,252,
%T A007622 272,280,306,342,360,380,420,462,495,504,506,552,600,630,650,660,
%U A007622 702,756,812,840,858,870,930,992,1056,1092,1122,1190,1260,1320,1332
%N A007622 Consider Leibniz's harmonic triangle (A003506) and look at the non-boundary 
               terms. Sequence gives numbers appearing in denominators, sorted.
%D A007622 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%D A007622 L. Comtet, Advanced Combinatorics, Reidel, 1974, p. 83, Problem 25.
%D A007622 D. Wells, The Penguin Dictionary of Curious and Interesting Numbers. 
               Penguin Books, NY, 1986, 35.
%H A007622 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               LeibnizHarmonicTriangle.html">Link to a section of The World of Mathematics.</
               a>
%t A007622 L[n_, 1] := 1/n; L[n_, m_] := L[n, m] = L[n - 1, m - 1] - L[n, m - 1]; 
               Take[ Union[ Flatten[ Table[ 1/L[n, m], {n, 3, 150}, {m, 2, Floor[n/
               2 + .5]}]]], 65]
%Y A007622 Sequence in context: A083209 A080714 A116368 this_sequence A056930 A064971 
               A130199
%Y A007622 Adjacent sequences: A007619 A007620 A007621 this_sequence A007623 A007624 
               A007625
%K A007622 nonn
%O A007622 1,1
%A A007622 N. J. A. Sloane (njas(AT)research.att.com), Robert G. Wilson v (rgwv(AT)rgwv.com), 
               Mira Bernstein (mira(AT)math.berkeley.edu)
%E A007622 More terms from Larry Reeves (larryr(AT)acm.org), Jul 25 2000. Rechecked 
               Jun 27 2003.