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!)
A187016 Seven-digit primes with derangement of digits 1..7. 1
2365471, 2375641, 2456371, 2456731, 2457613, 2467351, 2476351, 2516473, 2547613, 2547631, 2561743, 2576341, 2645371, 2651743, 2653741, 2657143, 2657341, 2716453, 2741653, 2761453, 2765143, 3452671, 3456721, 3462751, 3465271, 3467251, 3526741, 3546271, 3546721, 3576421, 3627451, 3672451, 3675241, 3752641, 3756241, 3756421 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
No digit is on its "right" place. There are exactly 143 such primes.
The only another possible case: four-digit primes with a derangement of digits 1..4 gives two primes 2143, 2341. There are no such primes with m=1,2,3,5,6,8,9 decimal digits 1..m.
LINKS
Zak Seidov, Table of n, a(n) for n = 1..143 (complete list)
EXAMPLE
2365471 is prime and 2 is not at 2nd place, 3 - not at 3rd place, 6 - not at 6th place, ..., 1 - not at the first place. Largest such prime is a(143)=7652413.
MATHEMATICA
derangQ[n_]:=Count[Thread[{n, Range[7]}], _?(#[[1]]==#[[2]]&)]==0; With[ {p7=Permutations[Range[7]]}, Select[p7, derangQ[#]&&PrimeQ[ FromDigits[ #]]&]] (* Harvey P. Dale, Sep 28 2017 *)
CROSSREFS
Cf. A000166.
Sequence in context: A204944 A184771 A210075 * A237487 A236484 A167438
KEYWORD
nonn,base,fini,full
AUTHOR
Zak Seidov, Mar 01 2011
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 March 29 11:43 EDT 2024. Contains 371278 sequences. (Running on oeis4.)