|
Search: id:A103893
|
|
|
| A103893 |
|
Number of distinct prime factors of prime(n)! / prime(n)# + 1. |
|
+0
3
|
|
| 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
(list; graph; listen)
|
|
|
OFFSET
|
1,5
|
|
|
COMMENT
|
Also the number of distinct prime factors of the P_n-th compositorial.
a(n) = A001221(A103890(n)).
a(31)>4 and its composite part is a 155-digit number.
|
|
LINKS
|
Dario Alejandro Alpern, Factorization using the Elliptic Curve Method
Hisanori Mishimar, Compositorial + 1 (n = 4 to 150)
R. Zumkeller, p(n)!/p(n )#+1
|
|
MATHEMATICA
|
bigomega[n_Integer] := Plus @@ Last /@ FactorInteger[n]; f[n_] := Prime[n]!/Product[Prime[i], {i, n}] + 1; Table[ f[n], {n, 27}] (from Robert G. Wilson v Mar 11 2005)
|
|
CROSSREFS
|
Cf. A103858.
Sequence in context: A012887 A079633 A060573 this_sequence A106448 A098007 A007554
Adjacent sequences: A103890 A103891 A103892 this_sequence A103894 A103895 A103896
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Reinhard Zumkeller (reinhard.zumkeller(AT)lhsystems.com), Feb 20 2005
|
|
EXTENSIONS
|
Corrected and extended by Robert G. Wilson v (rgwv(AT)rgwv.com), Mar 12 2005
|
|
|
Search completed in 0.002 seconds
|
