A178223 Numbers n such that the digits of n are also digits of n! (counting multiplicity).

1, 2, 4, 20, 21, 22, 23, 24, 25, 26, 27, 30, 31, 32, 33, 34, 35, 36, 37, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112

Offset: 1

Author

Michel Lagneau, Dec 20 2010

Keywords

• nonn
• base

Examples

			23 is in the sequence because 2 and 3 are digits of 23! = 25852016738884976640000 ;
28 is not in the sequence because 2 is not a digit of 28! = 304888344611713860501504000000.
11 is not in the sequence because 11! = 39916800 contains only a single "1".
		

Crossrefs

Cf. A064827

Programs

Mathematica

Reap[Do[a = DigitCount[n!]; b = DigitCount[n]; If[Min[a-b] >= 0, Sow[n]], {n, 1, 10^3}]][[2, 1]]