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 A301696 #23 Jun 08 2020 06:17:11 %S A301696 1,6,17,33,54,81,113,150,193,241,294,353,417,486,561,641,726,817,913, %T A301696 1014,1121,1233,1350,1473,1601,1734,1873,2017,2166,2321,2481,2646, %U A301696 2817,2993,3174,3361,3553,3750,3953,4161,4374,4593,4817,5046,5281,5521,5766 %N A301696 Partial sums of A219529. %H A301696 Colin Barker, <a href="/A301696/b301696.txt">Table of n, a(n) for n = 0..1000</a> %H A301696 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (2,-1,1,-2,1). %F A301696 From _Colin Barker_, Mar 26 2018: (Start) %F A301696 G.f.: (1 + x)^4 / ((1 - x)^3*(1 + x + x^2)). %F A301696 a(n) = 2*a(n-1) - a(n-2) + a(n-3) - 2*a(n-4) + a(n-5) for n>4. (End) %F A301696 From _G. C. Greubel_, May 27 2020: (Start) %F A301696 a(n) = (ChebyshevU(n, -1/2) - ChebyshevU(n-1, -1/2) + 8*(3*n*(n+1) +1))/9. %F A301696 a(n) = ( A131713(n) + 8*A028896(n) + 8 )/9. (End) %p A301696 A301696:= n-> (8*(3*n*(n+1) +1) + `mod`(n+2, 3) - `mod`(n+1, 3))/9; %p A301696 seq(A301696(n), n=0..60); # _G. C. Greubel_, May 27 2020 %t A301696 Table[(Mod[n+2, 3] - Mod[n+1, 3] + 8*(3*n*(n+1) +1))/9, {n,0,60}] (* _G. C. Greubel_, May 27 2020 *) %o A301696 (PARI) Vec((1 + x)^4 / ((1 - x)^3*(1 + x + x^2)) + O(x^60)) \\ _Colin Barker_, Mar 26 2018 %o A301696 (Sage) [(24*n*(n+1)+8 + (n+2)%3 - (n+1)%3 )/9 for n in (0..60)] # _G. C. Greubel_, May 27 2020 %Y A301696 Cf. A219529. %K A301696 nonn,easy %O A301696 0,2 %A A301696 _N. J. A. Sloane_, Mar 25 2018