A067012 Absolute composites: every permutation of digits (dropping any leading zeros) is a composite number.

4, 6, 8, 9, 12, 15, 18, 21, 22, 24, 25, 26, 27, 28, 33, 36, 39, 40, 42, 44, 45, 46, 48, 49, 51, 52, 54, 55, 56, 57, 58, 60, 62, 63, 64, 65, 66, 68, 69, 72, 75, 77, 78, 80, 81, 82, 84, 85, 86, 87, 88, 90, 93, 94, 96, 99, 102, 105, 108, 111, 114, 116, 117, 120, 122, 123

Offset: 1

Author

Lior Manor, Dec 26 2001

Keywords

• base
• nonn

Examples

			18 is a term since it is composite and the permutation 81 is composite too.
		

Links

• T. D. Noe, Table of n, a(n) for n = 1..10000

Crossrefs

Subsequence of A067013.

Programs

Mathematica

t={}; Do[l1=Table[FromDigits[k], {k,Permutations[IntegerDigits[n]]}]; If[Select[l1,PrimeQ] == {} && FreeQ[l1,1] == True, AppendTo[t,n]],{n,123}]; t  (* Jayanta Basu, May 03 2013  *)