|
| |
|
|
A064490
|
|
Smallest prime with number of decimal digits equal to n-th prime.
|
|
4
| |
|
|
11, 101, 10007, 1000003, 10000000019, 1000000000039, 10000000000000061, 1000000000000000003, 10000000000000000000009, 10000000000000000000000000331, 1000000000000000000000000000057
(list; graph; refs; listen; history; 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:
|
|
|
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) ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Sep 16 2009]
|
|
|
CROSSREFS
| Cf. A064489.
Sequence in context: A070854 A075767 A080176 * A080439 A098153 A020449
Adjacent sequences: A064487 A064488 A064489 * A064491 A064492 A064493
|
|
|
KEYWORD
| base,easy,nonn
|
|
|
AUTHOR
| Jason Earls (zevi_35711(AT)yahoo.com), Oct 04 2001
|
|
|
EXTENSIONS
| More terms from James A. Sellers (sellersj(AT)math.psu.edu), Oct 08 2001
OFFSET changed from 0,1 to 1,1 by` Harry J. Smith (hjsmithh(AT)sbcglobal.net), Sep 16 2009
|
| |
|
|
