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 A132920 #16 Mar 09 2025 17:03:56
%S A132920 1,3,9,18,35,63,112,196,342,595,1034,1794,3107,5369,9255,15912,27285,
%T A132920 46665,79610,135490,230076,389873,659364,1113108,1875925,3156543,
%U A132920 5303637,8899086,14913047,24961635,41734804,69706384,116311602,193898719,322961870,537493302
%N A132920 a(n) = n*Fibonacci(n) + binomial(n, 2).
%H A132920 Andrew Howroyd, <a href="/A132920/b132920.txt">Table of n, a(n) for n = 1..1000</a>
%H A132920 <a href="/index/Rec#order_07">Index entries for linear recurrences with constant coefficients</a>, signature (5,-8,2,6,-4,-1,1).
%F A132920 From _Andrew Howroyd_, Aug 10 2018: (Start)
%F A132920 a(n) = 5*a(n-1) - 8*a(n-2) + 2*a(n-3) + 6*a(n-4) - 4*a(n-5) - a(n-6) + a(n-7).
%F A132920 G.f.: x*(1 - 2*x + 2*x^2 - 5*x^3 + 5*x^4)/((1 - x)^3*(1 - x - x^2)^2). (End)
%e A132920 a(4) = 18 = 3 + 4 + 5 + 6.
%t A132920 Table[n*Fibonacci[n]+Binomial[n,2],{n,36}] (* _James C. McMahon_, Mar 09 2025 *)
%o A132920 (PARI) a(n) = n*fibonacci(n) + binomial(n, 2); \\ _Andrew Howroyd_, Aug 10 2018
%o A132920 (PARI) Vec((1 - 2*x + 2*x^2 - 5*x^3 + 5*x^4)/((1 - x)^3*(1 - x - x^2)^2) + O(x^40)) \\ _Andrew Howroyd_, Aug 10 2018
%Y A132920 Row sums of A132919.
%K A132920 nonn,easy
%O A132920 1,2
%A A132920 _Gary W. Adamson_, Sep 05 2007
%E A132920 Name changed and terms a(11) and beyond from _Andrew Howroyd_, Aug 10 2018