A115662 Nonpalindromic n which have the same number of distinct prime divisors as the reverse of n.

12, 13, 15, 16, 17, 21, 23, 26, 28, 31, 32, 36, 37, 39, 45, 51, 54, 56, 57, 58, 61, 62, 63, 65, 68, 69, 71, 73, 75, 79, 82, 85, 86, 93, 96, 97, 107, 108, 113, 115, 116, 117, 122, 123, 125, 128, 129, 132, 135, 143, 144, 149, 153, 155, 156, 157, 158, 159, 162, 163

Offset

1,1

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Example

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

Mathematica

npnQ[n_]:=!PalindromeQ[n]&&PrimeNu[n]==PrimeNu[IntegerReverse[n]]; Select[ Range[ 200], npnQ] (* Harvey P. Dale, Oct 26 2020 *)

Crossrefs

Cf. A001221, A115661.

Sequence in context: A112655 A308919 A048026 * A354746 A136200 A096514

Adjacent sequences: A115659 A115660 A115661 * A115663 A115664 A115665

Keyword

base,nonn

Author

Giovanni Resta, Jan 29 2006

Status

approved