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 A195163 #56 Sep 15 2022 13:07:45
%S A195163 0,1,1000,2997,5992,9985,14976,20965,27952,35937,44920,54901,65880,
%T A195163 77857,90832,104805,119776,135745,152712,170677,189640,209601,230560,
%U A195163 252517,275472,299425,324376,350325,377272,405217,434160,464101,495040,526977,559912,593845,628776
%N A195163 1000-gonal numbers: a(n) = n*(499*n - 498).
%C A195163 a(A271470(n)) is a perfect square. In fact, a(A271470(n)) = A271105(n) if the first term of a(n) is 1. - _Muniru A Asiru_, Apr 10 2016
%H A195163 Vincenzo Librandi, <a href="/A195163/b195163.txt">Table of n, a(n) for n = 0..10000</a>
%H A195163 M. A. Asiru, <a href="http://dx.doi.org/10.1080/0020739X.2016.1164346">All square chiliagonal numbers</a>, Int J Math Educ Sci Technol, 47:7(2016), 1123-1134.
%H A195163 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (3,-3,1).
%F A195163 a(n) = 998*n*(n-1)/2 + n, according to the common formula for s-gonal numbers, a(n) = (s-2)*n*(n-1)/2 + n. - _Sergey Pavlov_, Aug 14 2015
%F A195163 G.f.: x*(1+997*x)/(1-x)^3. - _R. J. Mathar_, Sep 12 2011
%F A195163 E.g.f.: exp(x)*x*(1 + 499*x). - _Ilya Gutkovskiy_, Apr 10 2016
%F A195163 a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n >= 4. - _Muniru A Asiru_, Sep 12 2017
%p A195163 A195163:=n->n*(499*n - 498): seq(A195163(n), n=0..50); # _Wesley Ivan Hurt_, Sep 16 2017
%t A195163 LinearRecurrence[{3,-3,1},{0,1,1000},50] (* _Vincenzo Librandi_, Nov 25 2011 *)
%t A195163 PolygonalNumber[1000,Range[0,40]] (* _Harvey P. Dale_, Sep 15 2022 *)
%o A195163 (PARI) a(n)=n*(499*n-498) \\ _Charles R Greathouse IV_, Sep 11 2011
%o A195163 (PARI) x='x+O('x^99); concat(0, Vec(x*(1+997*x)/(1-x)^3)) \\ _Altug Alkan_, Apr 10 2016
%o A195163 (Magma) [n*(499*n-498): n in [0..45]]; // _Vincenzo Librandi_, Nov 25 2011
%o A195163 (JavaScript) function a(n){return 998*n*(n-1)/2+n} // _Sergey Pavlov_, Aug 14 2015
%o A195163 (GAP)
%o A195163 a:=[0,1,1000];; for n in [4..10^2] do a[n]:=3*a[n-1]-3*a[n-2]+*a[n-3]; od; a; # _Muniru A Asiru_, Sep 12 2017
%Y A195163 Cf. A000578, A092182.
%K A195163 nonn,easy
%O A195163 0,3
%A A195163 _Kausthub Gudipati_, Sep 10 2011