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 A069627 #7 Dec 23 2020 03:04:15
%S A069627 0,0,1,5,12,22,35,53,74,101,129,162,202,244,292,344,403,463,527,601,
%T A069627 676,762,844,937,1035,1138,1245,1355,1476,1597,1726,1862,2002,2149,
%U A069627 2300,2454,2621,2784,2957,3136,3323,3515,3707,3914,4119,4338,4551,4782,5012,5250
%N A069627 Sum_{k=1..n} floor(n*(n-1)/(2*k)).
%C A069627 The old entry with this sequence number was a duplicate of A072137.
%F A069627 a(n) ~ n^2 * (gamma + log(n))/2, where gamma is the Euler-Mascheroni constant A001620. - _Vaclav Kotesovec_, Dec 23 2020
%p A069627 f:=n->add(floor( n*(n-1)/(2*k) ),k=1..n );
%Y A069627 Cf. A006218, A118014.
%K A069627 nonn
%O A069627 0,4
%A A069627 _N. J. A. Sloane_, Oct 28 2008