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 A026044 #11 Apr 27 2019 10:04:25
%S A026044 22,33,49,70,97,132,176,229,292,367,455,556,671,802,950,1115,1298,
%T A026044 1501,1725,1970,2237,2528,2844,3185,3552,3947,4371,4824,5307,5822,
%U A026044 6370,6951,7566,8217,8905,9630,10393,11196,12040,12925,13852,14823,15839,16900,18007,19162,20366,21619,22922,24277
%N A026044 a(n) = (d(n)-r(n))/2, where d = A026043 and r is the periodic sequence with fundamental period (1,1,0,0).
%H A026044 <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (4,-7,8,-7,4,-1).
%F A026044 a(n)=(n + 5)*(2*n^2 + 11*n + 54)/12 - 1/4 - (1/4)*cos(Pi*n/2) - (1/4)*sin(Pi*n/2) [From _Richard Choulet_, Dec 13 2008]
%F A026044 G.f. x^5*( 22-55*x+71*x^2-71*x^3+50*x^4-15*x^5 ) / ( (x^2+1)*(x-1)^4 ). - _R. J. Mathar_, Jun 22 2013
%t A026044 LinearRecurrence[{4,-7,8,-7,4,-1},{22,33,49,70,97,132},60] (* _Harvey P. Dale_, Apr 27 2019 *)
%K A026044 nonn
%O A026044 5,1
%A A026044 _Clark Kimberling_