A081027 Primes that are not in A080608.

11, 19, 41, 61, 89, 101, 109, 149, 151, 181, 191, 199, 211, 227, 241, 251, 257, 277, 281, 349, 389, 401, 409, 419, 421, 449, 461, 491, 499, 521, 541, 557, 577, 587, 601, 619, 641, 661, 691, 727, 757, 787, 809, 811, 821, 827, 857, 877, 881, 887, 911, 919, 941

Offset

1,1

Comments

Repeated removal of a single digit must eventually result in a nonprime.

Undeletable primes. - Arkadiusz Wesolowski, Oct 18 2011

Links

Michael S. Branicky, Table of n, a(n) for n = 1..10000

Prog

(Python)
from sympy import isprime, prevprime
def c(n):
    if not isprime(n): return False
    if n < 10: return True
    s = str(n)
    si = (s[:i]+s[i+1:] for i in range(len(s)))
    return any(t[0] != '0' and c(int(t)) for t in si)
def ok(n):
    return isprime(n) and not c(n)
print([k for k in range(942) if ok(k)]) # Michael S. Branicky, Jan 27 2023

Crossrefs

Cf. A080608.

Sequence in context: A066738 A278799 A337508 * A322474 A084986 A034844

Adjacent sequences: A081024 A081025 A081026 * A081028 A081029 A081030

Keyword

nonn,base

Author

David W. Wilson, Mar 02 2003

Status

approved