login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A355516 a(n) is the number of distinct integer values of Product_{k=1..n} (2 + 1/t_k) with integers t_k > 1. 2
1, 2, 5, 11, 29, 70, 164, 392, 933 (list; graph; refs; listen; history; text; internal format)
OFFSET
2,2
LINKS
EXAMPLE
a(2) = 1: The only representable integer is 5 = (2 + 1/3) * (2 + 1/7).
a(3) = 2: 9 and 11 can be represented; 9 = (2 + 1/9) * (2 + 1/13) * (2 + 1/19) and 10 other ways; 11 = (2 + 1/3)*(2 + 1/5)*(2 + 1/7) = (2 + 1/3)^2 * (2 + 1/49).
PROG
(PARI) see link in A355626.
CROSSREFS
A355626 provides more information.
A355628 same problem with factors (3 + 1/t_k).
Cf. A355243.
Sequence in context: A215939 A309857 A117719 * A359661 A316769 A192785
KEYWORD
nonn,hard,more
AUTHOR
Hugo Pfoertner and Markus Sigg, Jul 16 2022
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 28 20:05 EDT 2024. Contains 371254 sequences. (Running on oeis4.)