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 A098995 #10 Nov 03 2017 09:56:47 %S A098995 0,0,0,0,1,57,812,6524,37309,169298,648216,2176923,6582869,18262399, %T A098995 47129249,114344261,262987603,577216181,1215552037,2467076907, %U A098995 4843870146,9229556242,17113017451,30949065535,54705281270,94677736245,160689668475,267828562140,438931138500 %N A098995 Number of permutations of [n] with exactly 4 descents which avoid the pattern 1324. %H A098995 T. D. Noe, <a href="/A098995/b098995.txt">Table of n, a(n) for n = 1..1000</a> %H A098995 <a href="/index/Rec#order_17">Index entries for linear recurrences with constant coefficients</a>, signature (17,-136,680,-2380,6188,-12376,19448,-24310,24310,-19448,12376,-6188,2380,-680,136,-17,1). %F A098995 G.f.: x^5*(1 + 40*x - 21*x^2 - 208*x^3 + 453*x^4 - 379*x^5 + 74*x^6 + 107*x^7 - 92*x^8 + 30*x^9 - 4*x^10) / (1 - x)^17. %o A098995 (PARI) concat(vector(4), Vec(x^5*(1 + 40*x - 21*x^2 - 208*x^3 + 453*x^4 - 379*x^5 + 74*x^6 + 107*x^7 - 92*x^8 + 30*x^9 - 4*x^10) / (1 - x)^17 + O(x^30))) \\ _Colin Barker_, Nov 03 2017 %Y A098995 Cf. A061552, A000292. %K A098995 easy,nonn %O A098995 1,6 %A A098995 _Mike Zabrocki_, Nov 05 2004