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 A155639 #22 Sep 08 2022 08:45:40
%S A155639 1,2,12,92,672,4652,31032,201812,1288992,8124572,50700552,313968932,
%T A155639 1932641712,11839990892,72260648472,439667406452,2668522016832,
%U A155639 16163719991612,97745259402792,590286253682372,3560791008422352
%N A155639 a(n) = 6^n-5^n+1^n.
%H A155639 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (12,-41,30).
%F A155639 G.f.: 1/(1-6*x)-1/(1-5*x)+1/(1-x).
%F A155639 E.g.f.: e^(6*x)-e^(5*x)+e^x.
%F A155639 a(n) = 11*a(n-1)-30*a(n-2)+20 with a(0)=1, a(1)=2. - _Vincenzo Librandi_, Jul 21 2010
%p A155639 A155639:=n->6^n - 5^n + 1: seq(A155639(n), n=0..20); # _Wesley Ivan Hurt_, Nov 20 2014
%t A155639 Table[6^n - 5^n + 1, {n, 0, 20}] (* _Wesley Ivan Hurt_, Nov 20 2014 *)
%t A155639 LinearRecurrence[{12,-41,30},{1,2,12},30] (* _Harvey P. Dale_, Aug 23 2016 *)
%o A155639 (Magma) [6^n - 5^n + 1 : n in [0..20]]; // _Wesley Ivan Hurt_, Nov 20 2014
%o A155639 (PARI) a(n)=6^n-5^n+1 \\ _Charles R Greathouse IV_, Sep 24 2015
%Y A155639 Cf. A155624, A155625, A155626, A155627, A155628, A155629, A155630, A155631, A155632, A155633, A155634, A155635, A155636, A155637, A155638.
%K A155639 nonn,easy
%O A155639 0,2
%A A155639 _Mohammad K. Azarian_, Jan 30 2009