A063464 Numbers k such that omega(k) = omega(k+2), where omega(k) is the number of distinct prime divisors of k.
2, 3, 5, 7, 9, 10, 11, 12, 17, 18, 20, 22, 23, 24, 25, 26, 27, 29, 33, 34, 36, 38, 41, 44, 46, 47, 48, 50, 52, 54, 55, 56, 59, 63, 71, 72, 74, 75, 79, 80, 81, 85, 86, 91, 92, 93, 94, 96, 98, 101, 104, 106, 107, 115, 116, 117, 122, 125, 130, 133, 134, 137, 138, 141, 142
Offset: 1
Links
- Amiram Eldar, Table of n, a(n) for n = 1..10000 (terms 1..1000 from Harry J. Smith)
Programs
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Mathematica
Select[Range[200],PrimeNu[#]==PrimeNu[#+2]&] (* Harvey P. Dale, Jun 20 2011 *)
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PARI
j=[]; for(n=1,350, if(omega(n)==omega(n+2),j=concat(j,n))); j
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PARI
{ n=0; for (m=1, 10^9, if (omega(m) == omega(m + 2), write("b063464.txt", n++, " ", m); if (n==1000, break)) ) } \\ Harry J. Smith, Aug 22 2009