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Number of distinct prime factors of (prime(n)+1)*(prime(n+1)+1)/4.
6

%I #13 Apr 26 2017 02:48:42

%S 1,2,2,2,3,2,3,3,3,3,2,3,4,3,2,3,4,3,3,3,3,4,4,3,3,4,3,4,4,3,3,4,5,4,

%T 4,3,3,4,4,4,5,4,3,3,4,3,3,4,5,4,4,4,4,4,4,4,4,3,3,4,4,4,5,4,3,4,3,4,

%U 5,4,4,4,4,5,4,4,4,3,4,5,5,3,4,5,5,4,3,4,5,4,4,4,4,4,4,5,4,4,3,3,4,4,5,6,4

%N Number of distinct prime factors of (prime(n)+1)*(prime(n+1)+1)/4.

%H Reinhard Zumkeller, <a href="/A079085/b079085.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = A001221(A079079(n)).

%t Table[PrimeNu[(Prime[n] + 1)*(Prime[n + 1] + 1)/4], {n, 1, 50}] (* _G. C. Greubel_, Apr 25 2017 *)

%o (Haskell)

%o a079085 = a001221 . a079079 -- _Reinhard Zumkeller_, Oct 08 2012

%o (PARI) for(n=1,50, print1(omega((prime(n) + 1)*(prime(n + 1) + 1)/4), ", ")) \\ _G. C. Greubel_, Apr 25 2017

%Y Cf. A079086.

%K nonn

%O 1,2

%A _Reinhard Zumkeller_, Dec 22 2002