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 A026061 #12 Mar 17 2021 10:18:11 %S A026061 22,40,63,92,127,170,220,278,344,420,505,600,705,822,950,1090,1242, %T A026061 1408,1587,1780,1987,2210,2448,2702,2972,3260,3565,3888,4229,4590, %U A026061 4970,5370,5790,6232,6695,7180,7687,8218,8772,9350,9952,10580,11233,11912,12617,13350,14110,14898 %N A026061 a(n) = (d(n)-r(n))/2, where d = A026060 and r is the periodic sequence with fundamental period (1,0,0,0). %H A026061 <a href="/index/Rec#order_07">Index entries for linear recurrences with constant coefficients</a>, signature (3,-3,1,1,-3,3,-1). %F A026061 G.f.: x^5*( 22-26*x+9*x^2+x^3+28*x^5-10*x^6-22*x^4 ) / ( (1+x)*(x^2+1)*(x-1)^4 ). - _R. J. Mathar_, Jun 23 2013 %K A026061 nonn,easy %O A026061 5,1 %A A026061 _Clark Kimberling_