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 A168214 #27 Feb 07 2022 01:47:48 %S A168214 1,11,51,192,669,2222,7135,22374,68916,209348,628916,1872269,5531641, %T A168214 16238866,47410139,137758585,398617683,1149205715,3302324374, %U A168214 9461757569,27038402095,77082571383,219276117983,622541323482,1764242459656 %N A168214 Least k such that Sum_{i=n..k} 1/i >= n. %H A168214 Northwolves, <a href="http://blog.csdn.net/northwolves/archive/2009/11/20/4844754.aspx">Harmonic number sum</a> %e A168214 1/2 + 1/3 + ... + 1/10 < 2, but 1/2 + 1/3 + ... + 1/11 >= 2, so a(2) = 11. %t A168214 a[n_] := k /. FindRoot[Sum[1/i, {i, n, k}] == n, {k, n*E^n}, WorkingPrecision -> 32] // Ceiling; Table[a[n], {n, 1, 25}] (* _Jean-François Alcover_, Jun 08 2013 *) %o A168214 (VBA) %o A168214 Sub Harmonic_number_sum() %o A168214 Dim s As Double, i As Long, j As Long, n As Long %o A168214 For n = 1 To 15 %o A168214 s = 0 %o A168214 For i = n To 1000000000 %o A168214 s = s + 1 / i %o A168214 If s >= n Then Exit For %o A168214 Next %o A168214 Debug.Print "a(" & n & ")=" & i: %o A168214 Next %o A168214 End Sub %o A168214 (PARI) a(n)=my(k=n,s);while((s+=1./k)<n,k++);k \\ _Charles R Greathouse IV_, Jun 17 2013 %Y A168214 Cf. A004080, A002387 %K A168214 easy,nice,nonn %O A168214 1,2 %A A168214 _Zhining Yang_, Nov 20 2009 %E A168214 a(18)-a(25) from _Donovan Johnson_, Jun 19 2010 %E A168214 Example edited by _Jon E. Schoenfield_, Dec 20 2014