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 A125849 #11 May 17 2023 11:22:34
%S A125849 0,0,0,1,14,62,220,547,1260,2444,4560,7685,12650,19466,29484,42567,
%T A125849 60760,83672,114240,151689,200070,258070,331100,417131,523204,646372,
%U A125849 795600,966797,1171170,1403234,1676780,1984655,2343600,2744496,3207424
%N A125849 a(n) = Sum_{m=1..n-1} floor(m(n-2)/2)^2.
%F A125849 G.f.: (x^3*(x^6+18*x^5+35*x^4+62*x^3+31*x^2+12*x+1))/((x+1)^4*(x-1)^6). - Maksym Voznyy (voznyy(AT)mail.ru), Jul 28 2009
%p A125849 for n from 0 to 15 do add( floor(m*(n-2)/2)^2,m=1..n-1) ; print(n,%) ; od: # _R. J. Mathar_
%t A125849 f[n_] := Sum[ Floor[m (n - 2)/2]^2, {m, n - 1}]; Table[ f@n, {n, 0, 35}] (* _Robert G. Wilson v_, Aug 03 2008 *)
%K A125849 nonn
%O A125849 0,5
%A A125849 _Jerry Metzger_, Jul 09 2008
%E A125849 More terms from _Robert G. Wilson v_, Aug 03 2008