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 A086354 #13 Feb 10 2019 03:40:06
%S A086354 2,4,8,6,6,8,6,6,1,8,8,2,6,2,2,4,8,2,1,6,2,2,6,8,2,8,2,8,2,2,8,6,6,2,
%T A086354 2,6,2,2,6,8,8,6,3,4,2,2,6,6,2,8,6,2,2,9,8,6,6,5,8,2,8,8,2,6,2,8,8,8,
%U A086354 5,8,8,8,2,8,6,4,8,6,2,7,1,8,8,4,2,8,8
%N A086354 Fixed point if (nonzero-digit product)-function at initial value 2^n is iterated.
%H A086354 Nathaniel Johnston, <a href="/A086354/b086354.txt">Table of n, a(n) for n = 1..10000</a>
%F A086354 a(n) = A051802(2^n) = fixed point of A051801(2^n).
%e A086354 n=20, 2^20=1048576, iteration list={1048576,6720,84,32,6}, so a(20)=6.
%p A086354 A051801 := proc(n) local d,j: d:=convert(n,base,10): return mul(`if`(d[j]=0,1,d[j]), j=1..nops(d)): end: A086354 := proc(n) local m: m:=2^n: while(length(m)>1)do m:=A051801(m): od: return m: end: seq(A086354(n),n=1..100); # _Nathaniel Johnston_, May 04 2011
%t A086354 prd[x_] := Apply[Times, DeleteCases[IntegerDigits[x], 0]] Table[FixedPoint[prd, 2^w], {w, 1, 128}]
%Y A086354 Cf. A051801, A051802, A086353-A086361, A029898, A010888.
%K A086354 base,easy,nonn
%O A086354 1,1
%A A086354 _Labos Elemer_, Jul 21 2003