cp's OEIS Frontend

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.

A382239 Numbers not divisible by any of their digits nor by the sum of their digits. Digit 0 is allowed (and does not divide anything).

This page as a plain text file.
%I A382239 #24 Apr 01 2025 17:53:01
%S A382239 23,29,34,37,38,43,46,47,49,53,56,57,58,59,67,68,69,73,74,76,78,79,83,
%T A382239 86,87,89,94,97,98,203,223,227,229,233,239,249,253,257,259,263,267,
%U A382239 269,277,283,289,293,299,307,323,329,334,337,338,343,346,347,349,353,356,358,359,367,373,374,376
%N A382239 Numbers not divisible by any of their digits nor by the sum of their digits.  Digit 0 is allowed (and does not divide anything).
%C A382239 From a suggestion by _Sergio Pimentel_.
%H A382239 Robert Israel, <a href="/A382239/b382239.txt">Table of n, a(n) for n = 1..10000</a>
%F A382239 n^k << a(n) < 2^n for n > 5 where k = log(10)/log(9). - _Charles R Greathouse IV_, Mar 20 2025
%e A382239 a(5) = 38 is included because 38 is not divisible by 3, 8 or 3 + 8 = 11.
%e A382239 a(30) = 203 is included because 203 is not divisible by 2, 0, 3 or 2 + 0 + 3 = 5.
%p A382239 filter:= proc(n) local L;
%p A382239   L:= subs(0=NULL,convert(n,base,10));
%p A382239   not ormap(t -> n mod t = 0, [op(L),convert(L,`+`)])
%p A382239 end proc:
%p A382239 select(filter, [$1..1000]);
%t A382239 s= {};Do[t=Select[IntegerDigits[n],#>0&];AppendTo[t,Total[t]];If[NoneTrue[t,Mod[n,#]==00&],AppendTo[s,n]],{n,376}];s (* _James C. McMahon_, Mar 21 2025 *)
%o A382239 (Python)
%o A382239 def ok(n):
%o A382239     d = list(map(int, str(n)))
%o A382239     return (s:=sum(d)) and n%s!=0 and all(n%di!=0 for di in set(d)-{0})
%o A382239 print([k for k in range(1, 377) if ok(k)]) # _Michael S. Branicky_, Apr 01 2025
%Y A382239 Subsequence of A052383.
%Y A382239 Cf. A038772, A082943, A382237.
%K A382239 nonn,base
%O A382239 1,1
%A A382239 _Robert Israel_, Mar 19 2025