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A272768
Greatest prime number with prime(n) prime digits.
2
73, 773, 77773, 7777753, 77777777573, 7777777777573, 77777777777775557, 7777777777777777577, 77777777777777777775353, 77777777777777777777777775737, 7777777777777777777777777777333, 7777777777777777777777777777777773553, 77777777777777777777777777777777777777323
OFFSET
1,1
LINKS
MATHEMATICA
a[n_] := Block[{p=7(10^Prime[n]-1)/9-1}, While[{} != Intersection[ IntegerDigits@p, {0, 1, 4, 6, 8, 9}], p = NextPrime[p, -1]]; p]; Array[a, 13] (* Giovanni Resta, May 06 2016 *)
PROG
(PARI) isok(n) = {if (isprime(n), vd = vecsort(digits(n), , 8); for (i=1, #vd, if (!isprime(vd[i]), return (0))); return (1); ); }
a(n) = {gp = 7*(10^prime(n)-1)/9; while (!isok(gp), gp = precprime(gp-2)); gp; } \\ Michel Marcus, May 06 2016
CROSSREFS
Sequence in context: A137835 A063784 A066101 * A100412 A169830 A197341
KEYWORD
nonn,base
AUTHOR
Pierre CAMI, May 06 2016
EXTENSIONS
More terms from Michel Marcus, May 06 2016
a(57) in the b-file corrected by Giovanni Resta, May 06 2016
STATUS
approved