

A098037


Number of prime divisors, counted with multiplicity, of the sum of two consecutive primes.


4



1, 3, 3, 3, 4, 3, 4, 3, 3, 4, 3, 3, 4, 4, 4, 5, 5, 7, 3, 6, 4, 5, 3, 3, 4, 4, 4, 6, 3, 6, 3, 3, 4, 7, 5, 4, 7, 4, 4, 6, 6, 4, 8, 4, 5, 3, 3, 5, 5, 4, 4, 7, 4, 3, 5, 4, 6, 3, 4, 4, 8, 6, 3, 6, 5, 7, 3, 5, 5, 5, 4, 4, 4, 5, 3, 3, 3, 4, 6, 5, 6, 4, 8, 4, 5, 3, 3, 5, 5, 4, 3, 4, 3, 5, 3, 4, 3, 5, 5, 7, 6, 7, 3, 5, 4
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OFFSET

1,2


COMMENTS

Clearly sum of two consecutive primes prime(x) and prime(x+1) has more than 2 prime divisors for all x > 1.


LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000


FORMULA

a(n) = A001222(A001043(n)).  Michel Marcus, Feb 15 2014


EXAMPLE

Prime(2) + prime(3) = 2*2*2, 3 factors, the second term in the sequence.


MATHEMATICA

PrimeOmega[Total[#]]&/@Partition[Prime[Range[110]], 2, 1] (* Harvey P. Dale, Jun 14 2011 *)


PROG

(PARI) b(n) = for(x=1, n, y1=(prime(x)+prime(x+1)); print1(bigomega(y1)", "))


CROSSREFS

Cf. A071215.
Sequence in context: A239963 A084501 A198020 * A079108 A165605 A230194
Adjacent sequences: A098034 A098035 A098036 * A098038 A098039 A098040


KEYWORD

easy,nonn


AUTHOR

Cino Hilliard, Sep 10 2004


EXTENSIONS

Definition corrected by Andrew S. Plewe, Apr 08 2007


STATUS

approved



