A239747 Super-prime leaders: right-truncatable primes p with property that appending any single decimal digit to p does not produce a prime.

53, 317, 599, 797, 2393, 3793, 3797, 7331, 23333, 23339, 31193, 31379, 37397, 73331, 373393, 593993, 719333, 739397, 739399, 2399333, 7393931, 7393933, 23399339, 29399999, 37337999, 59393339, 73939133

Offset

1,1

Comments

The name "super-prime leaders" is not due to the author.

References

Joe Roberts, Lure of the Integers, The Mathematical Association of America, 1992, p. 292.

Links

Table of n, a(n) for n=1..27.

Chris Caldwell, The Prime Glossary, Right-truncatable prime

G. L. Honaker, Jr. and Chris Caldwell, Prime Curios! 53

Kvant magazine, The simplest prime numbers, (in Russian) No 11, 1979. (beware of typo)

Eric Weisstein's World of Mathematics, Truncatable Prime

Index entries for sequences related to truncatable primes

Formula

A024770 INTERSECT A119289.

Example

2393 belongs to this sequence because 2393, 239, 23 and 2 are all prime; 10*2393 + k, for k = 0 to 9, are all composite.

Prog

(PARI) f=1; for(n=2, 73939133, v=n; t=1; while(isprime(n), if(!Mod(f, n^2)==0, t=t*n); c=n; n=(c-lift(Mod(c, 10)))/10); if(n==0, f=f*t); n=v); s=Set(factor(f)[, 1]); for(k=1, #s, p=s[k]; if(!Mod(f, p^2)==0, print1(p, ", ")));

Crossrefs

Subsequence of A024770 and of A119289.

Sequence in context: A108878 A096325 A140042 * A261335 A174441 A094249

Adjacent sequences: A239744 A239745 A239746 * A239748 A239749 A239750

Keyword

nonn,base,fini,full

Author

Arkadiusz Wesolowski, Mar 26 2014

Status

approved