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 A286590 #21 Feb 16 2021 04:33:26 %S A286590 1,3,9,21,33,45,81,153,165,201,393,405,441,645,873,885,921,1113,1125, %T A286590 1161,1365,2313,2565,3765,4005,5913,5925,5961,6153,6165,6201,6405, %U A286590 7353,7641,8805,9045,15993,16281,17433,26085,26325,36393,36645,46233,46245,46281,46473,46485,46521,46725,47673 %N A286590 Numbers that are divisible by the product of their factorial base digits (A208575). %C A286590 After the initial 1, all terms are multiples of three. %H A286590 Amiram Eldar, <a href="/A286590/b286590.txt">Table of n, a(n) for n = 1..500</a> (terms 1..120 from Antti Karttunen) %H A286590 <a href="/index/Fa#facbase">Index entries for sequences related to factorial base representation</a> %t A286590 max = 8; Select[Range[max!], FreeQ[(d = IntegerDigits[#, MixedRadix[Range[max, 2, -1]]]), 0] && Divisible[#, Times @@ d] &] (* _Amiram Eldar_, Feb 16 2021 *) %o A286590 (Scheme, with _Antti Karttunen_'s IntSeq-library) %o A286590 (define A286590 (MATCHING-POS 1 1 (lambda (n) (let ((k (A208575 n))) (and (not (zero? k)) (zero? (modulo n k))))))) %Y A286590 Cf. A007489 (a subsequence), A208575, A118363. %Y A286590 Cf. A007602 (for base-10 analog). %K A286590 nonn,base %O A286590 1,2 %A A286590 _Antti Karttunen_, Jun 18 2017