OFFSET
1,1
COMMENTS
Terms in this sequence have at least 8 digits in base 7, i.e., are larger than 7^7, since sum(d_i 7^i) = sum(d_i) (mod 6), and 0+1+2+3+4+5+6 is divisible by 3. So there must be at least one repeated digit, which may not be 0 nor 6 neither odd (else the resulting number is even). The smallest terms are therefore of the form "1022...." in base 7, where "...." is a permutation of "3456", cf. examples.
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
EXAMPLE
The smallest base-7 pandigital primes are "10223465", "10223564", "10225364", "10225436", "10226354" and "10226453", written in base 7.
MATHEMATICA
Select[Range[10^6], Min @ DigitCount[#, 7] > 0 && PrimeQ[#] &] (* Amiram Eldar, Apr 13 2021 *)
PROG
(PARI) base7(n)={ local(a=[n%7]); while(0<n\=7, a=concat(n%7, a)); a }
forprime(p=7^7, 7^7*1.1, #Set(base7(p))==7 & print1(p", "))
CROSSREFS
KEYWORD
nonn,base
AUTHOR
M. F. Hasler, May 30 2010
EXTENSIONS
Edited by Charles R Greathouse IV, Aug 02 2010
STATUS
approved