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 A225864 #13 May 24 2024 18:38:57
%S A225864 12,21,115,511,1112,1121,1211,11711,13111,17111,31111,71111,111112,
%T A225864 121111,211111,1111115,1111117,1111171,1111511,1115111,1151111,
%U A225864 1511111,1711111,5111111,7111111,111111115,111111151,111111311,111111511,111115111,111131111,111151111
%N A225864 Composite numbers for which both sum and product of digits are primes.
%H A225864 Chai Wah Wu, <a href="/A225864/b225864.txt">Table of n, a(n) for n = 1..10000</a>
%t A225864 d[n_] := IntegerDigits[n]; t={}; Do[If[!PrimeQ[n] && PrimeQ[Plus@@(x=d[n])] && PrimeQ[Times@@x], AppendTo[t,n]], {n,2*10^6}]; t
%t A225864 Select[Range[72*10^5],CompositeQ[#]&&AllTrue[{Total[IntegerDigits[#]],Times@@ IntegerDigits[ #]},PrimeQ]&] (* The program generates the first 25 terms of the sequence. *) (* _Harvey P. Dale_, May 24 2024 *)
%o A225864 (Python)
%o A225864 from __future__ import division
%o A225864 from sympy import isprime
%o A225864 A225864_list = []
%o A225864 for l in range(1,20):
%o A225864 plist, q = [p for p in [2,3,5,7] if isprime(l-1+p)], (10**l-1)//9
%o A225864 for i in range(l):
%o A225864 for p in plist:
%o A225864 r = q+(p-1)*10**i
%o A225864 if not isprime(r):
%o A225864 A225864_list.append(r) # _Chai Wah Wu_, Aug 15 2017
%Y A225864 Cf. A046713, A225863.
%K A225864 nonn,base
%O A225864 1,1
%A A225864 _Jayanta Basu_, May 18 2013
%E A225864 Extended by _T. D. Noe_, May 18 2013