The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A098037 Number of prime divisors, counted with multiplicity, of the sum of two consecutive primes. 4

%I #17 Jan 22 2020 06:13:30

%S 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,

%T 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,

%U 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

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

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

%H Amiram Eldar, <a href="/A098037/b098037.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = A001222(A001043(n)). - _Michel Marcus_, Feb 15 2014

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

%t PrimeOmega[Total[#]]&/@Partition[Prime[Range[110]],2,1] (* _Harvey P. Dale_, Jun 14 2011 *)

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

%Y Cf. A071215.

%K easy,nonn

%O 1,2

%A _Cino Hilliard_, Sep 10 2004

%E Definition corrected by _Andrew S. Plewe_, Apr 08 2007

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified June 3 16:56 EDT 2024. Contains 373063 sequences. (Running on oeis4.)