A007810 Largest prime with n distinct decimal digits.

7, 97, 983, 9871, 98731, 987631, 9876413, 98765431, 987654103

Offset: 1

Author

N. B. Backhouse (sx52(AT)liverpool.ac.uk)

Keywords

• nonn
• fini
• base
• full

Comments

Differs from A071361 from a(7) on. - M. F. Hasler, May 03 2017

References

• J.-M. De Koninck, Ces nombres qui nous fascinent, Entry 9871, p.194, Ellipses, Paris 2008.

Crossrefs

Cf. A071360, A071361, A071362, A071363.

Programs

Mathematica

Table[Module[{k=NextPrime[10^n-1,-1]},While[Max[DigitCount[k]]>1, k = NextPrime[ k,-1]];k],{n,9}] (* Harvey P. Dale, Sep 16 2019 *)

PARI

A007810(n,p=sum(k=1,n,(9+k-n)*10^k)/10)={until(#Set(digits(p--))==n&&isprime(p),);p} \\ M. F. Hasler, May 03 2017