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 A166375 #16 May 11 2016 00:42:59
%S A166375 0,1,3,4,7,11,16,20,24,31,39,44,53,63,74,80,92,103,117,128,141,157,
%T A166375 174,186,200,219,237,252,273,293,316,332,352,377,403,420,445,473,500,
%U A166375 520,548,575,607,634,663,695,730,756,786,819,853,884,921,959,998
%N A166375 a(n) = sum (floor (j^2/n)) taken over 1 <= j <= n-1.
%H A166375 G. C. Greubel, <a href="/A166375/b166375.txt">Table of n, a(n) for n = 2..1000</a>
%F A166375 a(n) = A014817(n) - n. - _R. J. Mathar_, Jul 21 2015
%p A166375 A166375 := proc(n)
%p A166375 add( floor(j^2/n),j=1..n-1) ;
%p A166375 end proc: # _R. J. Mathar_, Jul 21 2015
%t A166375 Table[Sum[Floor[k^2/n], {k, 1, n - 1}], {n, 2, 100}] (* _G. C. Greubel_, May 10 2016 *)
%o A166375 (PARI) a(n) = sum(j=1,n-1, j^2\n) \\ _Michel Marcus_, Jun 20 2013
%Y A166375 Row sums of A166373. Cf. A014817.
%K A166375 nonn
%O A166375 2,3
%A A166375 _Christopher Hunt Gribble_, Oct 13 2009