Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A077622
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A077622 Number of numbers <= prime(n)# having n prime factors, where prime(n)# = A002110(n) is the n-th primorial. +0
4
1, 2, 7, 27, 190, 1621, 17271 (list; graph; listen)
OFFSET

1,2

COMMENT

a(n) = A077618(A002110(n)), see A077621.

EXAMPLE

a(3)=7, as there are 7 numbers <= prime(3)# = 2*3*5 = 30 having 3 prime factors: 8=2*2*2, 12=2*2*3, 18=2*3*3, 20=2*2*5, 27=3*3*3, 28=2*2*7, and 30=2*3*5.

CROSSREFS

Cf. A001222.

Adjacent sequences: A077619 A077620 A077621 this_sequence A077623 A077624 A077625

Sequence in context: A036783 A060017 A058800 this_sequence A137108 A099815 A123363

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Nov 12 2002

EXTENSIONS

17271 from Sascha Kurz (sascha.kurz(AT)uni-bayreuth.de), Jan 04 2003

page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified October 15 09:18 EDT 2008. Contains 145015 sequences.


AT&T Labs Research