login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A256118 Nine-digit zeroless pandigital numbers that are concatenation of three 3-digit prime numbers in increasing order. 1
127463859, 127643859, 149257683, 149257863, 149263587, 149263857, 149563827, 149653827, 157463829, 157643829, 163457829, 163547829, 239461587, 239461857, 239587641, 239641857, 241367859, 241673859, 241769853, 241853967, 251389467 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The sequence is finite with last term a(136) = 659743821.

LINKS

Zak Seidov, Table of n, a(n) for n = 1..136

EXAMPLE

(127, 463, 859) is the least triple of 3-digit primes together using each of nine digits 1..9 exactly once. Hence a(1) = 127463859.

MATHEMATICA

fQ[n_] := Block[{d = DigitCount@ n}, And[Max@ d == 1, Last@ d == 0, Plus @@ d == 9, n == FromDigits@ Flatten[IntegerDigits /@ Select[FromDigits /@ Partition[IntegerDigits@ n, 3], PrimeQ]]]]; Select[FromDigits /@ DeleteDuplicates[Flatten /@ (Sort@ Partition[IntegerDigits@ #, 3] & /@ FromDigits /@ Permutations[Range@ 9])], fQ@ # &] (* Michael De Vlieger, Mar 15 2015 *)

pnioQ[n_]:=Module[{idn=Partition[n, 3], a, b, c}, {a, b, c}=FromDigits/@ idn; a<b<c && AllTrue[{a, b, c}, PrimeQ]]; FromDigits/@ Select[ Permutations[ Range[ 9]], pnioQ] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Oct 18 2016 *)

CROSSREFS

Cf. A050278, A115301 (3 primes unsorted).

Sequence in context: A319065 A334346 A115301 * A036341 A184648 A258262

Adjacent sequences:  A256115 A256116 A256117 * A256119 A256120 A256121

KEYWORD

nonn,base,fini,full

AUTHOR

Zak Seidov, Mar 15 2015

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 8 19:29 EDT 2020. Contains 336298 sequences. (Running on oeis4.)