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!)
A085643 Refines sequence A078812 using permutations and products of exponents on least prime signatures. 3
1, 2, 1, 3, 4, 1, 4, 6, 4, 6, 1, 5, 8, 12, 9, 12, 8, 1, 6, 10, 16, 9, 12, 36, 8, 12, 24, 10, 1, 7, 12, 20, 24, 15, 48, 36, 27, 16, 72, 32, 15, 40, 12, 1, 8, 14, 24, 30, 16, 18, 60, 48, 72, 54, 20, 96, 144, 54, 16, 20, 120, 80, 18, 60, 14, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
The shape sequence for this table is A000041. Row sums in the example are A000079, A006906 and A001906.
LINKS
EXAMPLE
When the signatures (A025487) are listed in A036035 order the number of permutations of the exponents begin
1, 1 1, 1 2 1, 1 2 1 3 1, 1 2 2 3 3 4 1, ... b(n) and the products begin
1, 2 1, 3 2 1, 4 3 4 2 1, 5 4 6 3 4 2 1, ... c(n) thus we can write
1, 2 1, 3 4 1, 4 6 4 6 1, 5 8 12 9 12 8 1, ... a(n) = b(n)*c(n)
CROSSREFS
Cf. A078812.
Sequence in context: A104471 A174828 A305309 * A174829 A132110 A039912
KEYWORD
nonn,tabf
AUTHOR
Alford Arnold, Aug 15 2003
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 29 08:59 EDT 2024. Contains 371268 sequences. (Running on oeis4.)