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 A387204 #14 Aug 29 2025 11:40:33 %S A387204 0,6,23,57,115,205,336,518,762,1080,1485,1991,2613,3367,4270,5340, %T A387204 6596,8058,9747,11685,13895,16401,19228,22402,25950,29900,34281,39123, %U A387204 44457,50315,56730,63736,71368,79662,88655,98385,108891,120213,132392,145470,159490,174496 %N A387204 a(n) = n*(n + 1)*(n^2 + 17*n + 54)/24. %H A387204 Paolo Xausa, <a href="/A387204/b387204.txt">Table of n, a(n) for n = 0..10000</a> %H A387204 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (5,-10,10,-5,1). %F A387204 a(n) = [x^n] (-2*x^3 + 7*x^2 - 6*x)/(x - 1)^5. %F A387204 a(n) = [x^n] Pochhammer(x, 4)*(x + 1)^n. %p A387204 a := n -> n*(n + 1)*(n^2 + 17*n + 54)/24: seq(a(n), n = 0..41); %t A387204 A387204[n_] := n*(n + 1)*(n*(n + 17) + 54)/24; %t A387204 Array[A387204, 50, 0] (* _Paolo Xausa_, Aug 29 2025 *) %Y A387204 Cf. A387152 (row 4). %K A387204 nonn,easy,new %O A387204 0,2 %A A387204 _Peter Luschny_, Aug 27 2025