Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A047823
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A047823 Becomes prime after exactly 4 iterations of f(x) = sum of prime factors of x. +0
1
62, 69, 124, 133, 190, 194, 201, 206, 207, 213, 217, 219, 226, 235, 238, 248, 249, 254, 282, 286, 303, 309, 310, 314, 355, 380, 386, 388, 406, 411, 412, 426, 447, 451, 452, 458, 469, 476, 483, 489, 496, 505, 508, 553, 564, 572, 598, 602, 603, 606, 620, 621 (list; graph; listen)
OFFSET

1,1

COMMENT

f(x) = sum of prime factors without multiplicity, so that f(1500) = 2+3+5 = 10.

CROSSREFS

Sequence in context: A024804 A025340 A048127 this_sequence A044997 A138172 A074772

Adjacent sequences: A047820 A047821 A047822 this_sequence A047824 A047825 A047826

KEYWORD

nonn

AUTHOR

David W. Wilson (davidwwilson(AT)comcast.net)

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 August 29 17:54 EDT 2008. Contains 143238 sequences.


AT&T Labs Research