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 A101165 #13 Sep 08 2022 08:45:16 %S A101165 0,3,15,43,94,175,293,455,668,939,1275,1683,2170,2743,3409,4175,5048, %T A101165 6035,7143,8379,9750,11263,12925,14743,16724,18875,21203,23715,26418, %U A101165 29319,32425,35743,39280,43043,47039,51275,55758,60495,65493,70759 %N A101165 a(n) = (7*n^3 + 6*n^2 + 5*n) / 6. %C A101165 a(n) = A001845(n) - A000292(n+1) = A101164(n+3,3) for n>0. %F A101165 From _Chai Wah Wu_, May 29 2016: (Start) %F A101165 a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4). %F A101165 G.f.: x*(x^2 + 3*x + 3)/(x - 1)^4. %F A101165 (End) %o A101165 (Magma)[(7*n^3 + 6*n^2 + 5*n) / 6: n in [0..40]]; // _Vincenzo Librandi_, Dec 26 2010 %Y A101165 Cf. A005449, A101166. %K A101165 nonn %O A101165 0,2 %A A101165 _Reinhard Zumkeller_, Dec 03 2004