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!)
A102845 Number of prime factors of the sum of the first n odd primes. 1

%I #10 Sep 13 2016 15:05:44

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

%T 3,2,4,7,2,8,3,5,2,4,4,3,2,3,4,4,2,4,1,9,1,4,3,6,2,6,1,6,2,5,1,4,2,5,

%U 3,3,1,4,3,5,1,6,2,3,2,4,3,4,3,2,2,5,2,7,2,4,2,8,3,4,1,2,4,4,2,5,4,2,4,2,2

%N Number of prime factors of the sum of the first n odd primes.

%C Prime factors counted with multiplicity. - _Harvey P. Dale_, Sep 13 2016

%H Harvey P. Dale, <a href="/A102845/b102845.txt">Table of n, a(n) for n = 1..1000</a>

%e a(2)=3 because 3+5=8=2*2*2;

%e a(3)=2 because 3+5+7=15=3*5.

%t PrimeOmega[Accumulate[Prime[Range[2,110]]]] (* _Harvey P. Dale_, Sep 13 2016 *)

%o (PARI) for(n=1,105,print1(bigomega(sum(k=1,n,prime(k+1))),",")) (Shepherd)

%K easy,nonn

%O 1,2

%A _Giovanni Teofilatto_, Feb 28 2005

%E More terms from _Rick L. Shepherd_, May 18 2005

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 April 18 11:02 EDT 2024. Contains 371779 sequences. (Running on oeis4.)