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 A103845 #10 Nov 21 2013 12:48:38
%S A103845 1,2,4,13,85,925,16633,482329,22669417,1722875617,211913700769,
%T A103845 42170826452833,13579006117811905,7074662187380001985,
%U A103845 5963940223961341672513,8134814465483270041306369
%N A103845 Product of first n Lucas numbers, plus one.
%C A103845 Prime for n = 1, 3, 6; semiprime for n = 2, 4, 7, 8, 9, 10, 13, 14, 15, 23, 26. a(n) asymptotic to Phi^A000217(n).
%F A103845 a(n) = Product[Lucasi[k], {k, 1, n}]+1. a(n) = Product[A000217(k), {k, 1, n}]+1.
%F A103845 a(n) = A070825(n)+1, n>0. - R. J. Mathar, Dec 22 2010
%e A103845 a(10) = 1 * 3 * 4 * 7 * 11 * 18 * 29 * 47 * 76 * 123 + 1 = 211913700769 = 349 * 607202581 which is semiprime.
%t A103845 Join[{1},Rest[FoldList[Times,1,LucasL[Range[20]]]]+1] (* _Harvey P. Dale_, Oct 25 2011 *)
%Y A103845 Cf. A000045, A000204, A000217, A052449, A103815.
%K A103845 easy,nonn
%O A103845 0,2
%A A103845 _Jonathan Vos Post_, Mar 30 2005