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!)
A090057 Numbers n divisible by exactly two nontrivial permutations (rearrangements) of the digits of n. 5
1050, 1080, 3105, 5100, 5400, 7020, 7030, 9207, 9801, 10010, 10050, 10080, 10098, 10200, 10206, 20020, 20160, 20250, 20304, 20400, 20500, 20790, 21000, 21060, 30015, 30030, 30105, 30240, 30420, 30450, 30600, 35100, 40040, 40050 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Trivial permutations are identified as (1) permutation = n, or (2) when n mod 10=0, permutations of n's digits which result in shifting only trailing zeros to the most significant side of n where they drop off, such that permutation = n/10^z, where z <= the number of trailing zeros of n. So if n were 1809000, the following permutations would be excluded as trivial: 1809000, 0180900, 0018090, 0001809.
LINKS
EXAMPLE
a(3)=3105 because 3105 is divisible by both 135 and 1035, two nontrivial permutations of 3105. a(8)=9207 because 9207 is divisible by both 279 and 297, two nontrivial permutations of 9207.
CROSSREFS
Sequence in context: A030083 A184203 A015064 * A287173 A204753 A252391
KEYWORD
nonn,base
AUTHOR
Chuck Seggelin (barkeep(AT)plastereddragon.com), Nov 21 2003
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 July 22 23:31 EDT 2024. Contains 374544 sequences. (Running on oeis4.)