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 A155104 #21 Sep 17 2016 00:19:33
%S A155104 1,5,45,765,25245,1640925,211679325,54401586525,27908013887325,
%T A155104 28605714234508125,58613108466507148125,240137905387279785868125,
%U A155104 1967449858837983285617548125,32236665937060356134843526028125
%N A155104 Numbers appearing in the fourth column of A155103.
%F A155104 a(n) = prod(k=2..n) (1+2^k), n>1. - _Mats Granvik_, _Simone Severini_, Dec 04 2010
%F A155104 a(n) = A028362(n+1)/3. - _Vladimir Reshetnikov_, Sep 16 2016
%e A155104 a(1)=1, a(2)=1*5, a(3)=1*5*9, a(4)=1*5*9*17, a(5)=1*5*9*17*33, a(6)=1*5*9*17*33*65 and so on. See A000051 for continuation.
%t A155104 Table[QPochhammer[-4, 2, n - 1], {n, 14}] (* _Arkadiusz Wesolowski_, Oct 29 2012 *)
%Y A155104 Cf. A000051, A155105.
%K A155104 nonn
%O A155104 1,2
%A A155104 _Mats Granvik_, Jan 20 2009
%E A155104 More terms from _Mats Granvik_, Dec 05 2010