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 A098771 #9 Mar 07 2018 19:09:00 %S A098771 1,2,3,4,5,6,7,8,9,38,58,66,87,568,766,2799,6478,6785,26486,36685, %T A098771 36893,64788,66758,67586,69664,77686,276895,467683,474668,488973, %U A098771 548678,587667,658648,666369,668954,839666,939669,958968,968765,2386698 %N A098771 Numbers n such that sigma(n)=sigma(d_1)*sigma(d_2)*...*sigma(d_k) where d_1 d_2 ... d_k is the decimal expansion of n. %C A098771 Number of terms of this sequence up to 15000000 is 72. Has this sequence at least one multi-digit prime term? %e A098771 97888745 is in the sequence because sigma(97888745) = 117936000 = sigma(9)*sigma(7)*sigma(8)*sigma(8)*sigma(8)*sigma(7)*sigma(4)*sigma(5). %t A098771 Do[If[h=IntegerDigits[n];l=Length[h];!MemberQ[h, 0]&&DivisorSigma[ 1, n]==Product[DivisorSigma[1, h[[k]]], {k, l}], Print[n]] {n, 100000000}] %t A098771 Select[Range[24*10^5],DivisorSigma[1,#]==Times@@DivisorSigma[1, IntegerDigits[ #]]&] (* _Harvey P. Dale_, Mar 07 2018 *) %Y A098771 Cf. A098684, A098685. %K A098771 base,nonn %O A098771 1,2 %A A098771 _Farideh Firoozbakht_, Oct 03 2004