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 A074047 #8 Jan 22 2014 05:06:05
%S A074047 1,1,1,3,7,31,331,12795,4642051,60935796571,283646808320375611,
%T A074047 17285560913056915909539455163,
%U A074047 4902995236325455290013100337511909917402705547
%N A074047 a(n)=a(n-1)*a(n-2)*a(n-3)*(1/a(n-1)+1/a(n-2)+1/a(n-3)) starting with a(1)=a(2)=a(3)=1.
%C A074047 Using the simplified formula which extends the original one to terms that may be zero, one could prefix the values (1, 1, 0), cf. A121810. See also A203761 and references therein. - _M. F. Hasler_, Jan 01 2013
%F A074047 a(n) tends towards a(n-1)^phi and 1.22376...^(phi^n) where phi=(1+sqrt(5))/2=1.6180339887...
%F A074047 a(n)=a(n-1)*a(n-2)+a(n-3)*a(n-1)+a(n-2)*a(n-3). - _M. F. Hasler_, Jan 01 2013
%e A074047 a(7)=31*7*3*(1/31+1/7+1/3)=331.
%t A074047 RecurrenceTable[{a[n]==a[n-1]*a[n-2]+a[n-3]*a[n-1]+a[n-2]*a[n-3],a[1]==1,a[2]==1,a[3]==1},a[n],{n,1,15}] (* _Vaclav Kotesovec_, Jan 20 2014 *)
%Y A074047 Cf. A074046.
%K A074047 nonn
%O A074047 1,4
%A A074047 _Henry Bottomley_, Aug 14 2002