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 A365373 #9 Sep 04 2023 01:44:00 %S A365373 0,0,7,40,136,356,791,1568,2856,4872,7887,12232,18304,26572,37583, %T A365373 51968,70448,93840,123063,159144,203224,256564,320551,396704,486680, %U A365373 592280,715455,858312,1023120,1212316,1428511,1674496,1953248,2267936,2621927,3018792,3462312 %N A365373 a(n) = n*(3*n^4 + 15*n^3 + 25*n^2 - 15*n - 28)/60. %H A365373 <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (6,-15,20,-15,6,-1). %F A365373 a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6) for n > 5. %F A365373 O.g.f.: x^2*(7 - 2*x + x^2)/(1 - x)^6. %F A365373 E.g.f.: exp(x)*x^2*(210 + 190*x + 45*x^2 + 3*x^3)/60. %t A365373 a[n_]:= n*(3*n^4 + 15*n^3 + 25*n^2 - 15*n - 28)/60; Array[a,37,0] %o A365373 (Python) %o A365373 def A365373(n): return n*(n*(n*(n*(3*n + 15) + 25) - 15) - 28)//60 # _Chai Wah Wu_, Sep 04 2023 %Y A365373 Antidiagonal sums of A365372. %Y A365373 Cf. A068601 (2nd differences). %K A365373 nonn,easy %O A365373 0,3 %A A365373 _Stefano Spezia_, Sep 02 2023