A367008 - OEIS

%I #10 Jan 06 2024 09:21:52

%S 0,1,2,2,2,2,3,3,2,2,4,2,3,3,3,3,2,4,4,4,5,2,4,4,4,4,5,4,3,3,6,6,3,2,

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

%U 4,5,5,6,5,5,5,5,5,4,4,6,4,4,4,5,4,7,6

%N Number of prime factors of n*2^n + 1, counted with multiplicity.

%C The numbers n*2^n+1 are called Cullen numbers.

%H Amiram Eldar, <a href="/A367008/b367008.txt">Table of n, a(n) for n = 0..865</a>

%F a(n) = bigomega(n*2^n + 1) = A001222(A002064(n)).

%t Table[PrimeOmega[n*2^n + 1], {n, 0, 100}] (* _Amiram Eldar_, Jan 06 2024 *)

%o (PARI) a(n) = bigomega(n*2^n + 1); \\ _Amiram Eldar_, Jan 06 2024

%Y Cf. A002064, A001222, A366899, A367007.

%K nonn

%O 0,3

%A _Sean A. Irvine_, Oct 31 2023