A115661 Numbers n which have the same number of distinct prime divisors as the reverse of n.

1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12, 13, 15, 16, 17, 21, 22, 23, 26, 28, 31, 32, 33, 36, 37, 39, 44, 45, 51, 54, 55, 56, 57, 58, 61, 62, 63, 65, 66, 68, 69, 71, 73, 75, 77, 79, 82, 85, 86, 88, 93, 96, 97, 99, 101, 107, 108, 111, 113, 115, 116, 117, 121, 122, 123, 125, 128

Offset: 1

Author

Giovanni Resta, Jan 29 2006

Keywords

• base
• nonn

Examples

			omega(16)=omega(61)=1.
		

Links

• G. C. Greubel, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A001221, A115662.

Programs

Mathematica

Select[Range[130],PrimeNu[#]==PrimeNu[FromDigits[Reverse[ IntegerDigits[ #]]]]&] (* Harvey P. Dale, Jan 14 2012 *)