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 A066307 #20 Dec 04 2024 23:05:08
%S A066307 1,4,6,8,9,22,123,132,213,231,312,321,1124,1142,1214,1241,1412,1421,
%T A066307 2114,4112,4121,11125,11133,11152,11215,11222,11313,11331,11512,11521,
%U A066307 12115,12122,12151,12212,12221,13113,13131,13311,15112,15211,21115
%N A066307 Nonprimes whose sum of digits is equal to its product of digits.
%H A066307 Chai Wah Wu, <a href="/A066307/b066307.txt">Table of n, a(n) for n = 1..10000</a> (n = 1..516 from Harry J. Smith)
%e A066307 321 = 3*107, 3 + 2 + 1 = 6 = 3*2*1.
%t A066307 sdpdQ[n_]:=Module[{idn=IntegerDigits[n]},Total[idn]==Times@@idn]; Module[ {upto=25000, cs},cs=Complement[Range[upto],Prime[Range[PrimePi[upto]]]];Select[cs,sdpdQ]] (* _Harvey P. Dale_, Oct 14 2014 *)
%o A066307 (PARI) isok(k) = {if(isprime(k), 0, my(d=digits(k)); vecprod(d) == vecsum(d))} \\ _Harry J. Smith_, Feb 09 2010
%Y A066307 Composites and 1 from A034710.
%Y A066307 Cf. A034710, A066306.
%K A066307 base,nonn
%O A066307 1,2
%A A066307 _Labos Elemer_, Dec 13 2001