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 A220988 #7 Dec 29 2012 15:09:10
%S A220988 407353,4572972882642803,109245858982819139102535553,
%T A220988 2812355783638980226466572392952970603,
%U A220988 72895462357781065526518523423275265184080402953,1890603163831201090586603020695655490130990020251181357603
%N A220988 The right Aurifeuillian factor of 11^(22n+11) + 1.
%C A220988 The corresponding left Aurifeuillian factor is A220987.
%H A220988 Wikipedia, <a href="http://en.wikipedia.org/wiki/Cunningham_project">Cunningham Project</a>
%F A220988 a(n) = 161051 z^10 + 161051 z^9 + 73205 z^8 + 14641 z^7 - 1331 z^6 - 1331 z^5 - 121 z^4 + 121 z^3 + 55 z^2 + 11 z + 1 with z = 11^n.
%F A220988 Aurifeuillian factorization: 11^(22n+11) + 1 = (11^(2n+1) + 1) * A220987(n) * a(n).
%t A220988 Table[z = 11^n; 161051 z^10 + 161051 z^9 + 73205 z^8 + 14641 z^7 - 1331 z^6 - 1331 z^5 - 121 z^4 + 121 z^3 + 55 z^2 + 11 z + 1, {n, 0, 10}]
%Y A220988 Cf. A092440, A085601, A220978, A198410, A220979-A220990.
%K A220988 nonn,easy
%O A220988 0,1
%A A220988 _Stuart Clary_, Dec 27 2012