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 A074520 #22 Jun 12 2015 15:25:11
%S A074520 3,14,86,560,3698,24584,164306,1103480,7444418,50431304,342941426,
%T A074520 2340123800,16018069538,109949704424,756587236946,5217746494520,
%U A074520 36054040477058,249557173431944,1729973554578866,12008254925383640
%N A074520 1^n + 6^n + 7^n.
%H A074520 <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (14,-55,42).
%F A074520 G.f.:1/(1-x)+1/(1-6*x)+1/(1-7*x). E.g.f.: e^x+e^(6*x)+e^(7*x). [_Mohammad K. Azarian_, Dec 26 2008]
%F A074520 a(n) = 13*a(n-1) - 42*a(n-2) + 30, n>1. [_Gary Detlefs_, Jun 21 2010]
%F A074520 a(n) = A074619(n) + 1. - _Michel Marcus_, Nov 11 2013
%p A074520 A074520:=n->1^n + 6^n + 7^n; seq(A074520(n), n=0..100); # _Wesley Ivan Hurt_, Nov 11 2013
%t A074520 Table[1 + 6^n + 7^n, {n, 0, 20}]
%Y A074520 Cf. A001550, A001576, A034513, A001579, A074501 - A074580.
%K A074520 nonn,easy
%O A074520 0,1
%A A074520 _Robert G. Wilson v_, Aug 23 2002