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 A057877 a(n) = smallest n-digit prime in A057876. 2
 23, 113, 1531, 12239, 111317, 1111219, 11119291, 111111197, 1111113173, 11111133017, 111111189919, 1111111411337, 11111111161177, 111111111263311, 1111111111149119, 11111111111179913, 111111111111118771, 1111111111111751371, 11111111111111111131, 111111111111113129773, 1111111111111111337111 (list; graph; refs; listen; history; text; internal format)
 OFFSET 2,1 LINKS EXAMPLE 1531 gives primes 53, 131 and 151 after dropping digits 1, 5 and 3. MAPLE filter:= proc(n) local L, d, Lp;   if not isprime(n) then return false fi;   L:= convert(n, base, 10);   for d in convert(L, set) do     Lp:= subs(d=NULL, L);     if Lp=[] or Lp[-1] = 0 then return false fi;     if not isprime(add(Lp[i]*10^(i-1), i=1..nops(Lp))) then return false fi;   od;   true end proc: Res:= NULL: for t from 1 to 21 do   for x from (10^(t+1)-1)/9 by 2 do     if filter(x) then Res:= Res, x; break fi   od od: Res; # Robert Israel, Jul 13 2018 MATHEMATICA Do[k = (10^n - 1)/9; While[d = IntegerDigits[k]; !PrimeQ[k] || !PrimeQ[ FromDigits[ DeleteCases[d, 0]]] || !PrimeQ[ FromDigits[ DeleteCases[d, 1]]] || !PrimeQ[ FromDigits[ DeleteCases[d, 2]]] || !PrimeQ[ FromDigits[ DeleteCases[d, 3]]] || !PrimeQ[ FromDigits[ DeleteCases[d, 4]]] || !PrimeQ[ FromDigits[ DeleteCases[d, 5]]] || !PrimeQ[ FromDigits[ DeleteCases[d, 6]]] || !PrimeQ[ FromDigits[ DeleteCases[d, 7]]] || !PrimeQ[ FromDigits[ DeleteCases[d, 8]]] || !PrimeQ[ FromDigits[ DeleteCases[d, 9]]], k++ ]; Print[k], {n, 2, 19}] CROSSREFS Cf. A057876, A057877, A057878, A057879, A057880, A057881, A057882, A057883, A051362, A034302, A034303, A034304, A034305. Sequence in context: A288751 A070024 A111943 * A302530 A156568 A042026 Adjacent sequences:  A057874 A057875 A057876 * A057878 A057879 A057880 KEYWORD base,nonn AUTHOR Patrick De Geest, Oct 15 2000 EXTENSIONS Extended by Robert G. Wilson v, Dec 17 2002 More terms from Robert Israel, Jul 13 2018 STATUS approved

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Last modified December 6 22:25 EST 2021. Contains 349567 sequences. (Running on oeis4.)