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%I #17 Jan 27 2023 15:33:45
%S 11,19,41,61,89,101,109,149,151,181,191,199,211,227,241,251,257,277,
%T 281,349,389,401,409,419,421,449,461,491,499,521,541,557,577,587,601,
%U 619,641,661,691,727,757,787,809,811,821,827,857,877,881,887,911,919,941
%N Primes that are not in A080608.
%C Repeated removal of a single digit must eventually result in a nonprime.
%C Undeletable primes. - _Arkadiusz Wesolowski_, Oct 18 2011
%H Michael S. Branicky, <a href="/A081027/b081027.txt">Table of n, a(n) for n = 1..10000</a>
%o (Python)
%o from sympy import isprime, prevprime
%o def c(n):
%o if not isprime(n): return False
%o if n < 10: return True
%o s = str(n)
%o si = (s[:i]+s[i+1:] for i in range(len(s)))
%o return any(t[0] != '0' and c(int(t)) for t in si)
%o def ok(n):
%o return isprime(n) and not c(n)
%o print([k for k in range(942) if ok(k)]) # _Michael S. Branicky_, Jan 27 2023
%Y Cf. A080608.
%K nonn,base
%O 1,1
%A _David W. Wilson_, Mar 02 2003
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