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Triangle of the denominators of the almost-harmonic numbers: n-th term in m-th row is denominator of (sum{k=1 to m} 1/k) - 1/n, 1<=n<=m.
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%I #11 Oct 10 2019 14:03:47

%S 1,2,1,6,3,2,12,12,4,6,60,60,20,30,12,20,20,60,5,4,60,140,140,420,35,

%T 28,420,20,280,280,840,280,56,840,40,140,2520,2520,2520,2520,504,2520,

%U 360,1260,280,2520,2520,2520,2520,2520,2520,360,1260,280,2520,27720,27720

%N Triangle of the denominators of the almost-harmonic numbers: n-th term in m-th row is denominator of (sum{k=1 to m} 1/k) - 1/n, 1<=n<=m.

%e Triangle of almost-harmonic numbers begins:

%e 0

%e 1/2,1

%e 5/6,4/3,3/2

%e 13/12,19/12,7/4,11/6

%e 77/60,107/60,39/20,61/30,25/12

%t t[m_, n_] := Sum[1/k, {k, m}] - 1/n;Denominator @ Flatten @ Table[t[m, n], {m, 11}, {n, m}] (* _Ray Chandler_, Dec 14 2006 *)

%Y Cf. A125900.

%K frac,nonn,tabl

%O 1,2

%A _Leroy Quet_, Dec 13 2006

%E Extended by _Ray Chandler_, Dec 14 2006