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 A261893 #15 Mar 01 2023 13:11:32 %S A261893 1,7,23,55,109,191,307,463,665,919,1231,1607,2053,2575,3179,3871,4657, %T A261893 5543,6535,7639,8861,10207,11683,13295,15049,16951,19007,21223,23605, %U A261893 26159,28891,31807,34913,38215,41719,45431,49357,53503,57875,62479,67321,72407 %N A261893 a(n) = (n+1)^3 - n^2. %H A261893 Reinhard Zumkeller, <a href="/A261893/b261893.txt">Table of n, a(n) for n = 0..10000</a> %H A261893 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (4,-6,4,-1). %F A261893 a(n) = n^3 + 2*n^2 + 3*n + 1. %F A261893 a(n) = A000578(n+1) - A000290(n). %F A261893 O.g.f.: (1 + 3*x + x^2 + x^3)/(1 - x)^4. - _Bruno Berselli_, Jul 04 2016 %F A261893 E.g.f.: (1 + 6*x + 5*x^2 + x^3)*exp(x). - _Bruno Berselli_, Jul 04 2016 %t A261893 Table[n^3 + 2 n^2 + 3 n + 1, {n, 0, 50}] (* _Bruno Berselli_, Jul 04 2016 *) %t A261893 LinearRecurrence[{4,-6,4,-1},{1,7,23,55},50] (* _Harvey P. Dale_, Mar 01 2023 *) %o A261893 (Haskell) %o A261893 a261893 n = n * (n * (n + 2) + 3) + 1 %o A261893 a261893_list = zipWith (-) (tail a000578_list) a000290_list %o A261893 (PARI) vector(50, n, n--; n^3+2*n^2+3*n+1) \\ _Bruno Berselli_, Jul 04 2016 %o A261893 (Sage) [n^3+2*n^2+3*n+1 for n in range(50)]; # _Bruno Berselli_, Jul 04 2016 %o A261893 (Maxima) makelist(n^3+2*n^2+3*n+1, n, 0, 50); /* _Bruno Berselli_, Jul 04 2016 */ %o A261893 (Magma) [n^3+2*n^2+3*n+1: n in [0..50]]; // _Bruno Berselli_, Jul 04 2016 %Y A261893 Cf. A000290, A000578. %Y A261893 Subsequence of A167222. %K A261893 nonn,easy %O A261893 0,2 %A A261893 _Reinhard Zumkeller_, Sep 05 2015