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%I #23 Jan 21 2024 02:22:32
%S 0,0,2,1,2,2,2,2,4,2,3,4,4,5,5,3,5,3,4,6,5,4,5,6,9,1
%N Number of distinct prime factors of prime(n)! - prime(n)# + 1.
%C a(27) >= 4. - _Amiram Eldar_, Jan 21 2024
%H Factordb.com, <a href="http://factordb.com/index.php?query=103%21-103%23%2B1">Status of 103!-103#+1</a>.
%H Reinhard Zumkeller, <a href="/A103855/a103855.txt">prime(n)!-prime(n)#+1</a>.
%F a(n) = A001221(A103855(n)).
%t primorial[n_] := Product[Prime[i], {i, n}]; A103855[n_] := Prime[n]! - primorial[n] + 1; PrimeNu[Array[A103855, 20]] (* _G. C. Greubel_, May 09 2017 *)
%o (PARI) a(n) = omega(prime(n)! - prod(k=1, n, prime(k)) + 1); \\ _Michel Marcus_, Nov 06 2022
%Y Cf. A001221, A103855, A103893.
%K nonn,more
%O 1,3
%A _Reinhard Zumkeller_, Feb 20 2005
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