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A103893 Number of distinct prime factors of prime(n)! / prime(n)# + 1. 2
1, 1, 1, 1, 2, 3, 3, 4, 2, 3, 2, 4, 4, 5, 3, 2, 3, 4, 6, 5, 5, 5, 5, 6, 5, 4, 5, 3, 7, 5, 5, 8, 5 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,5
COMMENTS
Also the number of distinct prime factors of the P_n-th compositorial.
a(31) > 4 and its composite part is a 155-digit number.
a(34) >= 4. - Amiram Eldar, Jan 21 2024
LINKS
Factordb.com, Status of 139!/139#+1.
Reinhard Zumkeller, prime(n)!/prime(n)#+1.
FORMULA
a(n) = A001221(A103890(n)).
MATHEMATICA
bigomega[n_Integer] := Plus @@ Last /@ FactorInteger[n]; f[n_] := Prime[n]!/Product[Prime[i], {i, n}] + 1; Table[ f[n], {n, 27}] (* Robert G. Wilson v, Mar 11 2005 *)
CROSSREFS
Sequence in context: A251715 A361819 A304758 * A288159 A269526 A106448
KEYWORD
nonn,more
AUTHOR
Reinhard Zumkeller, Feb 20 2005
EXTENSIONS
Corrected and extended by Robert G. Wilson v, Mar 12 2005
a(31)-a(33) using factordb.com added by Amiram Eldar, Jan 21 2024
STATUS
approved

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Last modified March 28 07:46 EDT 2024. Contains 371235 sequences. (Running on oeis4.)