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 A050919 #28 May 03 2025 10:56:26
%S A050919 1,8,99,1030,9605,84036,705895,5764802,46118409,363182464,2824752491,
%T A050919 21750594174,166095446413,1259557135292,9495123019887,71213422649146,
%U A050919 531726889113617,3954718737782520,29311444762388083,216579008522089718,1595845325952240021,11729463145748964148
%N A050919 a(n) = n*7^n + 1.
%H A050919 Vincenzo Librandi, <a href="/A050919/b050919.txt">Table of n, a(n) for n = 0..1000</a>
%H A050919 Paul Leyland, <a href="http://www.leyland.vispa.com/numth/factorization/cullen_woodall/cw.htm">Factors of Cullen and Woodall numbers</a>.
%H A050919 Paul Leyland, <a href="http://www.leyland.vispa.com/numth/factorization/cullen_woodall/gcw.htm">Generalized Cullen and Woodall numbers</a>.
%H A050919 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (15,-63,49).
%F A050919 G.f.: -(42*x^2 - 7*x + 1)/((x-1)*(7*x-1)^2). - _Colin Barker_, Oct 14 2012
%F A050919 From _Elmo R. Oliveira_, May 03 2025: (Start)
%F A050919 E.g.f.: exp(x)*(1 + 7*x*exp(6*x)).
%F A050919 a(n) = 15*a(n-1) - 63*a(n-2) + 49*a(n-3).
%F A050919 a(n) = A036293(n) + 1. (End)
%t A050919 Table[n*7^n+1,{n,0,20}] (* or *) LinearRecurrence[{15,-63,49},{1,8,99},20] (* _Harvey P. Dale_, Nov 23 2013 *)
%o A050919 (Magma) [ n*7^n+1: n in [0..20]]; // _Vincenzo Librandi_, Sep 16 2011
%Y A050919 Cf. A002064, A036293.
%K A050919 nonn,easy
%O A050919 0,2
%A A050919 _N. J. A. Sloane_, Dec 30 1999