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A064490 Smallest prime with prime(n) decimal digits. 4
11, 101, 10007, 1000003, 10000000019, 1000000000039, 10000000000000061, 1000000000000000003, 10000000000000000000009, 10000000000000000000000000331, 1000000000000000000000000000057 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Harry J. Smith, Table of n, a(n) for n = 1..75

EXAMPLE

11 is the first prime with 2 decimal digits. 101 is the first prime with 3 decimal digits.

MAPLE

for n from 1 to 20 do p := ithprime(n): for i from 10^(p-1) to 10^p do if isprime(i) then printf(`%d, `, i); break; fi: od: od:

# second Maple program:

a:= n-> nextprime(10^(ithprime(n)-1)):

seq(a(n), n=1..15);  # Alois P. Heinz, Jun 24 2018

MATHEMATICA

Table[NextPrime[10^(n-1)], {n, Prime[Range[15]]}] (* Harvey P. Dale, Feb 06 2020 *)

PROG

(PARI) l(n)=ln=0; while(n, n=floor(n/10); ln++); return(ln); a=0; for(n=1, 10^6, x=l(prime(n)); if(isprime(x), b=x; if(b>a, a=b; print(prime(n)))))

(PARI) { for (n=1, 75, p=prime(n); a=nextprime(10^(p - 1)); write("b064490.txt", n, " ", a) ) } \\ Harry J. Smith, Sep 16 2009

CROSSREFS

Cf. A064489.

Sequence in context: A075767 A292014 A080176 * A080439 A098153 A020449

Adjacent sequences:  A064487 A064488 A064489 * A064491 A064492 A064493

KEYWORD

base,easy,nonn

AUTHOR

Jason Earls, Oct 04 2001

EXTENSIONS

More terms from James A. Sellers, Oct 08 2001

Offset changed from 0 to 1 by Harry J. Smith, Sep 16 2009

STATUS

approved

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Last modified July 8 04:16 EDT 2020. Contains 335504 sequences. (Running on oeis4.)