This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A081530 #13 Jan 22 2017 20:05:09
%S A081530 1,5,26,77,522,669,5772,13827,48610,55991,699612,785633,11359222,
%T A081530 12530955,13726712,29889983,550271934,593094837,12094689300,
%U A081530 12932216325,13780828710,14640022575,356714770680,376932115005,1986818142426
%N A081530 a(n) = running sum of the first n harmonic numbers, multiplied by the LCM of 1..n.
%C A081530 Consider triangle in A081525. Write terms in k-th row with denominator = LCM of terms in that row. Sequence gives sum of numerators of terms in n-th row.
%H A081530 G. C. Greubel, <a href="/A081530/b081530.txt">Table of n, a(n) for n = 1..1000</a>
%F A081530 a(n) = lcm(1..n)*(n+1)*(H(n+1)-1), where H(n) is the n-th harmonic number. - C. Ronaldo (aga_new_ac(AT)hotmail.com), Dec 19 2004
%F A081530 Equal to A001705(n) / A025527(n). - _Martin Fuller_, Jan 03 2006
%e A081530 (1), 2*(1 + 3/2), 6*(1 + 3/2 + 11/6), 12*(1 + 3/2 + 11/6 + 25/12).
%p A081530 H:=n->add(1/i,i=1..n):seq((n+1)*ilcm(seq(j,j=1..n))*(H(n+1)-1),n=1..30); # C. Ronaldo
%t A081530 Table[Sum[HarmonicNumber[k], {k, n}] LCM @@ Range[n], {n, 36}] (* _Wouter Meeussen_ *)
%Y A081530 Cf. A081525, A081526, A081527, A081528, A081529.
%Y A081530 Cf. A001705, A025527.
%K A081530 nonn
%O A081530 1,2
%A A081530 _Amarnath Murthy_, Mar 27 2003
%E A081530 More terms from _Wouter Meeussen_, Apr 13 2003