A228119 Numbers n such that n * (product of digits of n) + 1 is prime.

1, 2, 4, 6, 16, 21, 22, 23, 24, 25, 26, 27, 28, 29, 32, 34, 42, 52, 61, 65, 66, 69, 72, 83, 84, 86, 92, 98, 114, 123, 134, 138, 161, 165, 169, 176, 186, 192, 213, 216, 219, 222, 223, 228, 239, 249, 253, 256, 258, 259, 265, 273, 286, 289, 292, 293, 294, 297

Offset: 1

Author

Jayanta Basu, Aug 14 2013

Keywords

• nonn
• base

Examples

			16 is a member since 16 * (product of digits of 16) + 1 = 16*6 + 1 = 97 is a prime.
		

Links

• Jayanta Basu, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000040, A007954.

Programs

Mathematica

Select[Range[300], PrimeQ[(#*Times @@ IntegerDigits[#]) + 1] &]