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 A088942 #12 Jun 17 2017 03:53:50 %S A088942 0,60,390,1450,4045,9421,19361,36281,63326,104466,164592,249612, %T A088942 366547,523627,730387,997763,1338188,1765688,2295978,2946558,3736809, %U A088942 4688089,5823829,7169629,8753354,10605230,12757940,15246720,18109455,21386775 %N A088942 a(n)=60*sum(1<=i<=j<=k<=n,i^2*j/k). %C A088942 Always an integer. Can be expressed as a polynomial with rational coefficients of degree 5. %H A088942 <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (6,-15,20,-15,6,-1). %F A088942 a(n) = n/120 * (96n^4 + 765n^3 + 2210n^2 + 2275n + 1354). %F A088942 G.f.: x*(x^4-5*x^3+10*x^2+30*x+60) / (x-1)^6. - _Colin Barker_, Jun 15 2013 %o A088942 (PARI) a(n)=60*sum(k=1,n,sum(j=1,k,sum(i=1,j,i^2*j/k))) %Y A088942 Cf. A088941, A088943. %K A088942 nonn,easy %O A088942 0,2 %A A088942 _Benoit Cloitre_, Oct 25 2003