A243819 Composite numbers n such that every divisor of n greater than one contains the digit 0.
10201, 10403, 10609, 10807, 11009, 11021, 31007, 40501, 41303, 41309, 42907, 43709, 50803, 51409, 51809, 60701, 61307, 61903, 64307, 65509, 70801, 71609, 72203, 73027, 75007, 76409, 81709, 91607, 97049, 101909, 102313, 102919, 103121, 103927, 104131, 104333, 104339, 104939, 104957, 105163, 105949
Offset: 1
Examples
The divisors of 10201 are {1, 101, and 10201}. Except for 1 each has a 0 in its decimal expansion.
Links
- Amiram Eldar, Table of n, a(n) for n = 1..10000 (terms 1..2500 from Barbara W. Waddell and Robert G. Wilson v)
Programs
-
Mathematica
fQ[n_, dgt_] := Union[ MemberQ[#, dgt] & /@ IntegerDigits@ Rest@ Divisors@ n][[1]]; Select[ Range[2, 106000], !PrimeQ[#] && fQ[#, 0] &] cd0Q[n_]:=CompositeQ[n]&&AllTrue[Rest[Divisors[n]],DigitCount[#,10,0]>0&]; Select[Range[ 106000],cd0Q] (* Harvey P. Dale, Aug 15 2024 *)
Extensions
Definition slightly modified by Harvey P. Dale, Aug 15 2024