OFFSET
1,1
COMMENTS
A158124: initial digit may not be changed to a zero (and hence give a number with fewer digits).
A050249: initial digit may be changed to a zero.
For the following values 5, 6, 7, 8, 9, 10 of k, the number of terms < 10^k in this sequence is 0, 1, 8, 72, 589, 4977. - Jean-Marc Rebert, Nov 10 2015
Intersection of A227916 and A158124. So primes p that give another prime when the first digit is removed, but give a composite number when any one digit is modified in a way that does not change the digit count. - Jeppe Stig Nielsen, Jan 16 2022
LINKS
Jean-Marc Rebert, Table of n, a(n) for n = 1..589
Eric Weisstein's World of Mathematics, Weakly Prime
PROG
(PARI) forprime(p=2, 10^10, d=digits(p); !isprime(fromdigits(d[2..#d]))&&next(); for(k=1, #d, for(j=(k==1), 9, d[k]==j&&next(); e=d; e[k]=j; isprime(fromdigits(e))&&next(3))); print1(p, ", ")) \\ Jeppe Stig Nielsen, Jan 16 2022
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Eric W. Weisstein, Mar 13 2009
STATUS
approved