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 A028889 #12 Jun 20 2021 02:27:34 %S A028889 1,2,4,8,11,12,14,18,21,22,24,26,27,29,34,36,37,38,39,41,42,43,46,49, %T A028889 62,63,64,66,67,72,73,76,77,79,81,83,88,89,92,93,94,97,98,99,111,112, %U A028889 114,118,121,122,124,126,127,129,134,136,137,138,139,141,142,143,146,149,162,163,164,166,167 %N A028889 Numbers whose iterated product of digits is a power of 2. %H A028889 Harvey P. Dale, <a href="/A028889/b028889.txt">Table of n, a(n) for n = 1..1000</a> %e A028889 38 -> 3*8 = 24 -> 2*4 = 8 = 2^3. %t A028889 p2Q[n_]:=IntegerQ[Log[2,NestWhile[Times@@IntegerDigits[#]&,n,#>9&]]]; Select[ Range[200],p2Q] (* _Harvey P. Dale_, Sep 19 2019 *) %Y A028889 Cf. A031347, A028846, A028836. %K A028889 nonn,base %O A028889 1,2 %A A028889 _N. J. A. Sloane_ %E A028889 Extended (and corrected) by Scott Lindhurst (ScottL(AT)alumni.princeton.edu)