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A102862 Numbers of prime factors of the sum of the first n primes. 1

%I #13 Dec 22 2022 18:38:57

%S 1,1,2,1,3,1,2,2,4,2,6,1,3,1,4,2,5,2,4,3,4,2,3,3,4,4,5,2,5,4,5,2,4,2,

%T 3,2,5,2,3,5,3,3,3,2,4,2,3,2,5,3,4,6,4,2,2,3,4,2,2,1,3,3,3,1,2,2,3,3,

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

%N Numbers of prime factors of the sum of the first n primes.

%H Amiram Eldar, <a href="/A102862/b102862.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = A001222(A007504(n)). - _Amiram Eldar_, Mar 09 2020

%e a(3) = 2 because 2+3+5 = 10 = 2*5.

%e a(5) = 3 because 2+3+5+7+11 = 28 = 2*2*7.

%t PrimeOmega @ Accumulate @ Select[Range[230], PrimeQ] (* _Amiram Eldar_, Mar 09 2020 *)

%t PrimeOmega[Accumulate[Prime[Range[110]]]] (* _Harvey P. Dale_, Dec 22 2022 *)

%o (PARI) for(n=1,105,print1(bigomega(sum(k=1,n,prime(k))),",")) \\ _Rick L. Shepherd_, May 17 2005

%Y Cf. A001222, A007504.

%K nonn

%O 1,3

%A _Giovanni Teofilatto_, Mar 01 2005

%E More terms from _Rick L. Shepherd_, May 17 2005

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Last modified April 19 18:05 EDT 2024. Contains 371798 sequences. (Running on oeis4.)