A079085 Number of distinct prime factors of (prime(n)+1)*(prime(n+1)+1)/4.

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, 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, 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

Offset

1,2

Links

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Formula

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

Mathematica

Table[PrimeNu[(Prime[n] + 1)*(Prime[n + 1] + 1)/4], {n, 1, 50}] (* G. C. Greubel, Apr 25 2017 *)

Prog

(Haskell)
a079085 = a001221 . a079079  -- Reinhard Zumkeller, Oct 08 2012
(PARI) for(n=1, 50, print1(omega((prime(n) + 1)*(prime(n + 1) + 1)/4), ", ")) \\ G. C. Greubel, Apr 25 2017

Crossrefs

Cf. A079086.

Sequence in context: A266225 A248596 A076984 * A076869 A335925 A104307

Adjacent sequences: A079082 A079083 A079084 * A079086 A079087 A079088

Keyword

nonn

Author

Reinhard Zumkeller, Dec 22 2002

Status

approved