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A158125
Weakly prime numbers in the sense of A158124 but not A050249.
5
929573, 3070663, 5285767, 5974249, 7810223, 9262697, 9663683, 9700429, 10532453, 12968519, 19106729, 19158221, 19579907, 21825337, 23196157, 24328567, 29617897, 31181461, 31746383, 31839427, 36438379, 36745811, 37763641, 38585039, 38774851, 38888137, 39600559, 45412331, 45743483, 47500217, 47632271, 54127231, 56242891, 59816347
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
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