Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A140775
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A140775 A number n is included if p + n/p is prime for every prime p that divides n. +0
3
2, 6, 10, 22, 30, 34, 42, 58, 70, 78, 82, 102, 118, 130, 142, 190, 202, 210, 214, 274, 298, 310, 322, 330, 358, 382, 394, 442, 454, 462, 478, 510, 538, 562, 582, 610, 622, 658, 694, 714, 730, 742, 790, 838, 862, 922, 930, 970, 1002, 1038, 1042, 1110, 1138, 1198 (list; graph; listen)
OFFSET

1,1

COMMENT

All terms of this sequence are even and squarefree.

EXAMPLE

The primes dividing 70 are 2, 5, 7. Now, 2 + 70/2 = 37; 5 + 70/5 = 19; 7 + 70/7 = 17. Since 37, 19, and 17 are each prime, then 70 is included in this sequence.

MATHEMATICA

fQ[n_] := Block[{p = First@ Transpose@ FactorInteger@ n}, Union@ PrimeQ[p + n/p] == {True}]; Select[ Range[2, 1221], fQ@# &] - Robert G. Wilson v, (rgwv(AT)rgwv.com), May 30 2008

CROSSREFS

Cf. A140776, A140777.

Adjacent sequences: A140772 A140773 A140774 this_sequence A140776 A140777 A140778

Sequence in context: A103628 A034450 A112861 this_sequence A077064 A080715 A034168

KEYWORD

nonn

AUTHOR

Leroy Quet (qq-quet(AT)mindspring.com), May 29 2008

EXTENSIONS

More terms from Robert G. Wilson v, (rgwv(AT)rgwv.com), May 30 2008

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 6 12:54 EDT 2008. Contains 144667 sequences.


AT&T Labs Research