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 A370251 #18 Mar 25 2024 12:05:49 %S A370251 1,176,231,495,7040 %N A370251 Base-12 numbers k such that k = (product of nonzero digits of k) * (sum of digits of k) (written in base 10). %C A370251 There are only finitely many such numbers (Property 1' of Clerc). %H A370251 René-Louis Clerc, <a href="https://hal.science/hal-04235744">Quelques nombres de Niven-Harshad particuliers</a>, 2023. %H A370251 René-Louis Clerc, <a href="https://ut3-toulouseinp.hal.science/hal-04507547">Nombres S+P, maxSP, minSP et |P-S|</a>, hal-04507547 [math.nt], 2024. (In French) %e A370251 231 = 173_12, (1*7*3)*(1+7+3) = 21*11 = 231. %t A370251 Select[Range[5*10^4], Total[IntegerDigits[#, 12]]*Fold[Times, 1, Select[IntegerDigits[#, 12],#>0&]]==#&] (* _James C. McMahon_, Feb 14 2024 *) %o A370251 (PARI) isok(k, b) = my(d=select(x->(x>0), digits(k, b))); vecprod(d)*vecsum(d) == k; %o A370251 for (k=0, 10^10, if (isok(k, 12), print1(k, ", "))) %Y A370251 Cf. A366832, A367070, A066282, A062331, A023651, A038364, A038369, A062237. %K A370251 base,nonn,fini,more %O A370251 1,2 %A A370251 _René-Louis Clerc_, Feb 13 2024