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 A085611 #20 Aug 08 2021 01:53:38
%S A085611 0,0,0,1,6,12,32,57,73,144,210,255,394,516,520,833,1032,1182,1518,
%T A085611 1809,1927,2500,2904,3205,3836,4368,4768,5577,6258,6550,7780,8625,
%U A085611 9265,10496,11526,12403,13782,15012,15996,17689,19140,20218,22274,23961,25309,27588,29532,31209,33688
%N A085611 Difference between A007678(2n)/(2n) and (n-1)^2.
%C A085611 If we define b(n) by b(n)=local(nr,fn,cn); nr=0; fn=floor(n/2); cn=ceiling(n/2); forstep (i=n,4,-2,nr=nr+(i-2)*fn+(i-4)*cn); nr then a(n) is given by (A007678(2n)-b(2n))/(2n).
%C A085611 This b(n) is given by (n-2)*(2*n^2 - 4*n + 3*(-1)^n - 3)/8 for n > 1. - _R. J. Mathar_, Oct 18 2013
%F A085611 a(n) = A007678(2*n)/(2*n) - (n-1)^2. - _M. F. Hasler_, Aug 06 2021
%o A085611 (PARI) apply( {A085611(n)=A007678(2*n)/(2*n)-(n-1)^2}, [1..40]) \\ _M. F. Hasler_, Aug 05 2021
%Y A085611 Cf. A007678, A006533, A000290.
%K A085611 nonn
%O A085611 1,5
%A A085611 _Jon Perry_, Jul 08 2003
%E A085611 The last term seemed to be corrupted and has now been deleted. - _N. J. A. Sloane_, Oct 29 2006
%E A085611 Edited and more terms from _M. F. Hasler_, Aug 06 2021