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 A175898 #22 Oct 29 2022 04:49:36
%S A175898 1,6,26,76,186,386,726,1251,2031,3126,4626,6606,9176,12426,16486,
%T A175898 21461,27501,34726,43306,53376,65126,78706,94326,112151,132411,155286,
%U A175898 181026,209826,241956,277626,317126,360681,408601,461126,518586,581236,649426,723426
%N A175898 Expansion of (1+3*x+9*x^2+9*x^3+9*x^4+3*x^5+x^6) /( (1+x)^2 * (1-x)^5 ).
%H A175898 Harvey P. Dale, <a href="/A175898/b175898.txt">Table of n, a(n) for n = 0..1000</a>
%H A175898 <a href="/index/Rec#order_07">Index entries for linear recurrences with constant coefficients</a>, signature (3,-1,-5,5,1,-3,1).
%F A175898 a(n) = 55*n^2/24 +185*n/96 +59/64 +35*n^4/96 +35*n^3/48 +(5*n/32+5/64)*(-1)^n.
%F A175898 a(2n) = (55*n^2+25*n+6+35*n^4+35*n^3)/6.
%F A175898 a(n) = +3*a(n-1) -a(n-2) -5*a(n-3) +5*a(n-4) +a(n-5) -3*a(n-6) +a(n-7).
%t A175898 LinearRecurrence[{3,-1,-5,5,1,-3,1},{1,6,26,76,186,386,726},40] (* _Harvey P. Dale_, Feb 27 2012 *)
%o A175898 (PARI) Vec((1+3*x+9*x^2+9*x^3+9*x^4+3*x^5+x^6)/((1+x)^2*(1-x)^5)+O(x^99)) \\ _Charles R Greathouse IV_, Sep 26 2012
%o A175898 (PARI) a(n)=5*n*(7*n^3 + 14*n^2 + 44*n + 37 + 3*(-1)^n)\/96 + 1 \\ _Charles R Greathouse IV_, Jul 06 2017
%Y A175898 Bisections: A181342, A181343.
%K A175898 nonn,easy
%O A175898 0,2
%A A175898 _Jamil da SIlva_, Oct 11 2010
%E A175898 Edited by _R. J. Mathar_, Oct 12 2010