login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A052299 Minimal number of distinct prime factors of any composite number between n-th and (n+1)st primes. 0
1, 2, 1, 2, 1, 2, 2, 1, 3, 1, 2, 3, 2, 1, 2, 3, 1, 2, 2, 2, 1, 2, 2, 2, 3, 2, 2, 2, 1, 1, 2, 3, 2, 3, 2, 2, 2, 1, 2, 3, 2, 2, 2, 3, 2, 2, 2, 3, 2, 2, 3, 1, 1, 2, 2, 3, 2, 2, 3, 1, 2, 2, 3, 2, 2, 2, 1, 3, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 4, 2, 2, 2, 2, 2, 2, 2, 4, 2, 2, 2, 2, 2, 2, 2, 1, 3, 1, 2, 2, 2, 2, 4, 2, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..105.

EXAMPLE

n=81: p(81)=419, p(82)=421. The intermediate range of composites includes only 420=4*3*5*7 having 4 prime-factors, so a(81)=4;

MATHEMATICA

Min[PrimeNu[Range[#[[1]]+1, #[[2]]-1]]]&/@Partition[Prime[ Range[ 2, 110]], 2, 1] (* Harvey P. Dale, Mar 31 2012 *)

CROSSREFS

A052180, A052248.

Sequence in context: A118459 A274354 A083870 * A071854 A183025 A072410

Adjacent sequences:  A052296 A052297 A052298 * A052300 A052301 A052302

KEYWORD

nonn

AUTHOR

Labos Elemer, Feb 09 2000

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 9 19:47 EDT 2021. Contains 343746 sequences. (Running on oeis4.)