

A139092


a(n) = number of distinct prime divisors of (9+prime(n)!)/9.


4



3, 3, 2, 2, 2, 3, 2, 3, 4, 4, 5, 3, 3, 6, 5, 2, 3, 4, 3, 3, 4, 4, 4, 3, 7, 3, 3
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OFFSET

4,1


COMMENTS

Conjecture: all prime divisors in A139089 are distinct
a(31) >= 4.  Amiram Eldar, Feb 13 2020


LINKS

Table of n, a(n) for n=4..30.
FactorDB, Status of a(31) = (9+127!)/9.


FORMULA

a(n) = A001221(A139089(n)).  Amiram Eldar, Feb 13 2020


MATHEMATICA

a = {}; Do[w = (Prime[n]! + 9)/9; AppendTo[a, w], {n, 4, 16}]; a
PrimeNu[(9+Prime[Range[4, 25]]!)/9] (* Harvey P. Dale, Jul 25 2019 *)


CROSSREFS

Cf. A082672, A089085, A089130, A117141, A007749, A139056A139066, A020458, A139068, A137390, A139070A139075, A136019, A136020, A136026, A136027, A139089A139092.
Sequence in context: A133884 A065775 A096837 * A021305 A075788 A324080
Adjacent sequences: A139089 A139090 A139091 * A139093 A139094 A139095


KEYWORD

nonn,more


AUTHOR

Artur Jasinski, Apr 08 2008


EXTENSIONS

More terms from Jon E. Schoenfield, Jul 16 2010
a(23)a(30) using factordb.com from Amiram Eldar, Feb 13 2020


STATUS

approved



