|
|
A239682
|
|
Product_{i=1..n} A173557(i).
|
|
1
|
|
|
1, 1, 2, 2, 8, 16, 96, 96, 192, 768, 7680, 15360, 184320, 1105920, 8847360, 8847360, 141557760, 283115520, 5096079360, 20384317440, 244611809280, 2446118092800, 53814598041600, 107629196083200, 430516784332800, 5166201411993600, 10332402823987200
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,3
|
|
COMMENTS
|
This is the generalized factorial for A173557.
|
|
LINKS
|
|
|
FORMULA
|
|
|
EXAMPLE
|
The first five terms of A173557 are 1,1,2,1,4 so a(5)=4*1*2*1*1=8.
|
|
PROG
|
(Sage)
q=50 # change q for more terms
R=[prod([(x-1) for x in prime_divisors(n)]) for n in [1..q]]
[prod(R[0:i+1]) for i in [0..q-1]]
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|