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 A291987 #16 Sep 09 2017 21:43:29 %S A291987 1,1,3,6,14,20,45,69,135,210,378,576,1057,1561,2667,4110,6902,10220, %T A291987 17109,25485,41583,62250,99666,147960,238633,350881,553107,825126, %U A291987 1292942,1899620,2977821,4381269,6791127,10025730,15415722,22645296,34970545,51140521 %N A291987 Expansion of 1/((1-x)*(1-2*x^2)*(1-3*x^3)*(1-4*x^4)). %H A291987 Seiichi Manyama, <a href="/A291987/b291987.txt">Table of n, a(n) for n = 0..6271</a> %H A291987 <a href="/index/Rec#order_10">Index entries for linear recurrences with constant coefficients</a>, signature (1,2,1,1,-10,-2,-4,12,24,-24). %F A291987 a(n) = a(n-1) + 2*a(n-2) + a(n-3) + a(n-4) - 10*a(n-5) - 2*a(n-6) - 4*a(n-7) + 12*a(n-8) + 24*a(n-9) - 24*a(n-10) for n >= 11. - _Muniru A Asiru_, Sep 07 2017 %o A291987 (PARI) Vec(1/((1-x)*(1-2*x^2)*(1-3*x^3)*(1-4*x^4)) + O(x^100)) %o A291987 (GAP) %o A291987 a:=[1,1,3,6,14,20,45,69,135,210];; %o A291987 for n in [11..10^2] do a[n]:=a[n-1]+2*a[n-2]+a[n-3]+a[n-4]-10*a[n-5]-2*a[n-6]-4*a[n-7]+12*a[n-8]+24*a[n-9]-24*a[n-10]; od; a; # _Muniru A Asiru_, Sep 07 2017 %Y A291987 Cf. A291960, A291986, A291988. %K A291987 nonn,easy %O A291987 0,3 %A A291987 _Seiichi Manyama_, Sep 07 2017