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A127889 Smallest n-digit right-truncatable prime. 4
2, 23, 233, 2333, 23333, 233993, 2339933, 23399339 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Agrees with A088603 for 8 terms, but this sequence ends there while A088603 continues.

Right-truncatable means that the integer part of successive divisions by 10 always yields primes (or zero). - M. F. Hasler, Nov 07 2018

LINKS

Table of n, a(n) for n=1..8.

I. O. Angell and H. J. Godwin, On Truncatable Primes, Math. Comput. 31, 265-267, 1977.

Index entries for sequences related to truncatable primes

MAPLE

P:=proc(q) local i, j, n, ok; for i from 0 to 8 do for n from 1 to q do ok:=1;

for j from 1 to i do if not isprime(trunc(ithprime(n)/10^j)) then ok:=0;

break; fi; od; if ok=1 then print(ithprime(n)); break; fi;

od; od; end: P(23399339); # Paolo P. Lava, Oct 15 2013

PROG

(PARI) A127889=vector(8, n, p=concat(apply(t->primes([t, t+1]*10), if(n>1, p))); p[1]) \\ M. F. Hasler, Nov 07 2018

CROSSREFS

Cf. A024770, A050986, A088603, A127890.

Sequence in context: A100893 A198972 A065122 * A088603 A048549 A158191

Adjacent sequences:  A127886 A127887 A127888 * A127890 A127891 A127892

KEYWORD

base,nonn,fini,full

AUTHOR

Ray Chandler, Feb 04 2007

STATUS

approved

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Last modified February 16 12:48 EST 2019. Contains 320163 sequences. (Running on oeis4.)