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 A383911 #16 May 15 2025 06:56:01
%S A383911 1,20,200,1400,8000,40520,190400,852200,3692000,15640520,65225600,
%T A383911 268985000,1100372000,4475152520,18122340800,73156029800,294627068000,
%U A383911 1184523016520,4756148096000,19078784066600,76477758500000,306398995072520,1227060052251200,4912632802375400,19663709744588000
%N A383911 Expansion of Product_{k=0..4} (1 + k*x)/(1 - k*x).
%H A383911 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (10,-35,50,-24).
%F A383911 a(n) = 10*a(n-1) - 35*a(n-2) + 50*a(n-3) - 24*a(n-4) for n > 4.
%F A383911 a(n) = Sum_{k=0..4} |Stirling1(5,k+1)| * Stirling2(k+n,4).
%F A383911 a(n) = A383913(n) + 4*A383913(n-1) = 70*4^n - 140*3^n + 45*2^(n+1) - 20 for n > 0.
%o A383911 (PARI) a(n) = if(n==0, 1, 70*4^n-140*3^n+45*2^(n+1)-20);
%Y A383911 Column k=4 of A383900.
%Y A383911 Cf. A383913.
%K A383911 nonn,easy
%O A383911 0,2
%A A383911 _Seiichi Manyama_, May 14 2025