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 A155650 #20 Jan 14 2023 11:18:49
%S A155650 1,2,14,128,1106,9032,70994,543608,4085186,30275912,222009074,
%T A155650 1614529688,11664504866,83828316392,599858908754,4277376525368,
%U A155650 30411820662146,215703854542472,1526853641242034,10789535445362648
%N A155650 a(n) = 7^n - 6^n + 1.
%H A155650 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (14,-55,42).
%F A155650 G.f.: 1/(1-7*x)-1/(1-6*x)+1/(1-x).
%F A155650 E.g.f.: e^(7*x)-e^(6*x)+e^x.
%F A155650 a(n) = 13*a(n-1)-42*a(n-2)+30 with a(0)=1, a(1)=2. [_Vincenzo Librandi_, Jul 21 2010]
%p A155650 A155650:=n->7^n - 6^n + 1; seq(A155650(n), n=0..30); # _Wesley Ivan Hurt_, Jan 28 2014
%t A155650 Table[7^n - 6^n + 1, {n, 0, 30}] (* _Wesley Ivan Hurt_, Jan 28 2014 *)
%o A155650 (PARI) a(n)= 7^n-6^n+1 \\ _Charles R Greathouse IV_, Dec 22 2011
%K A155650 nonn,easy
%O A155650 0,2
%A A155650 _Mohammad K. Azarian_, Jan 31 2009