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
Examples
omega(16)=omega(61)=1.
Links
- Harvey P. Dale, Table of n, a(n) for n = 1..1000
Programs
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Mathematica
npnQ[n_]:=!PalindromeQ[n]&&PrimeNu[n]==PrimeNu[IntegerReverse[n]]; Select[ Range[ 200],npnQ] (* Harvey P. Dale, Oct 26 2020 *)