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 A055004 #13 Jun 09 2016 06:20:52
%S A055004 0,0,1,5,15,33,64,107,171,252,359,490,656,844,1079,1346,1656,2006,
%T A055004 2415,2859,3373,3927,4550,5233,5993,6793,7690,8653,9697,10809,12028,
%U A055004 13299,14695,16158,17731,19398,21174,23018,25017,27108,29318,31616
%N A055004 Boris Stechkin's function.
%D A055004 R. K. Guy, Unsolved Problems Number Theory, A17.
%H A055004 G. C. Greubel, <a href="/A055004/b055004.txt">Table of n, a(n) for n = 0..1000</a>
%p A055004 A055004 := proc(n) local m; add((m-1)*floor(n*(m-1)/m),m=2..n); end proc;
%t A055004 Table[Sum[(k - 1)*Floor[n*(k - 1)/k], {k, 2, n}], {n, 0, 100}] (* _G. C. Greubel_, Jun 06 2016 *)
%Y A055004 Cf. A063483.
%K A055004 nonn
%O A055004 0,4
%A A055004 _N. J. A. Sloane_, Jun 11 2000