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!)
A100950 Number of partitions of n into a coprime pair of a prime and a semiprime. 2
0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 3, 0, 2, 1, 1, 1, 5, 0, 2, 1, 2, 2, 4, 0, 3, 3, 5, 3, 4, 0, 2, 4, 4, 2, 4, 1, 5, 6, 3, 3, 6, 1, 4, 4, 6, 5, 4, 2, 4, 4, 7, 6, 6, 3, 3, 6, 7, 6, 4, 1, 3, 10, 7, 5, 7, 3, 6, 9, 6, 5, 5, 5, 4, 7, 8, 7, 7, 4, 6, 9, 8, 9, 4, 3, 7, 8, 8, 9, 8, 2, 4, 10, 11, 10, 6, 8, 7, 12, 9, 8, 6, 6, 5 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,11
COMMENTS
A100951(n)<=a(n)<=A100949(n)<=Min{A000720(n), A072000(n)}.
a(n) = A000040(i) + A001358(j) for some i and j, such that A000040(i) is not a factor of A001358(j).
LINKS
EXAMPLE
A100949(21) = #{7+2*7, 11+2*5, 17+2*2} = 3,
a(21) = #{11+2*5, 17+2*2} = 2.
CROSSREFS
Sequence in context: A052311 A181786 A164629 * A359867 A021335 A089595
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Nov 23 2004
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 3 04:01 EST 2024. Contains 370499 sequences. (Running on oeis4.)