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.

A082943 Positive numbers not divisible by any of their digits nor by the sum of their digits.

Original entry on oeis.org

23, 29, 34, 37, 38, 43, 46, 47, 49, 53, 56, 57, 58, 59, 67, 68, 69, 73, 74, 76, 78, 79, 83, 86, 87, 89, 94, 97, 98, 223, 227, 229, 233, 239, 249, 253, 257, 259, 263, 267, 269, 277, 283, 289, 293, 299, 323, 329, 334, 337, 338, 343, 346, 347, 349, 353, 356
Offset: 1

Views

Author

Meenakshi Srikanth (menakan_s(AT)yahoo.com), Apr 30 2003

Keywords

Comments

The definition implies that no digit is zero. - N. J. A. Sloane, Mar 27 2025

Examples

			38 is neither divisible by 3 nor 8 nor 11 (i.e. 3+8).
		

Crossrefs

Programs

  • Maple
    filter:= proc(n) local L;
      L:= convert(n,base,10);
      not member(0,L) and not ormap(t -> n mod t = 0, [op(L),convert(L,`+`)])
    end proc:
    select(filter, [$1..1000]); # Robert Israel, Mar 19 2025
  • Mathematica
    test1[n_] := Module[{dig = IntegerDigits[n]}, Union[Table[IntegerQ[n/dig[[i]]], {i, Length[dig]}]]] == {False};
    test2[n_] := Module[{dig = IntegerDigits[n]}, Not[IntegerQ[n/Sum[dig[[i]], {i, Length[dig]}]]]];
    Table[If[test1[n] && test2[n], n, 0], {n, 200}] // Union // Rest (* José María Grau Ribas, Feb 17 2010 *)
    ndQ[n_]:=Module[{idn=IntegerDigits[n]},FreeQ[idn,0]&&NoneTrue[n/ Join[ idn, {Total[idn]}],IntegerQ]]; Select[Range[2000],ndQ] (* Harvey P. Dale, Oct 19 2016 *)

Extensions

More terms from Harvey P. Dale, Oct 19 2016