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A154981
Primes with nonprime smallest digit.
2
11, 13, 17, 19, 31, 41, 47, 61, 67, 71, 89, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 241, 251, 271, 281, 307, 311, 313, 317, 331, 401, 409, 419, 421, 431, 449, 457, 461, 467, 479, 487, 491
OFFSET
1,1
COMMENTS
Nonprime digits in base 10 are 0, 1, 4, 6, 8 and 9.
LINKS
EXAMPLE
17 is in the sequence because its smallest digit is 1, which is not prime.
19 is in the sequence because its smallest digit is 1, which is not prime (neither is 9, for that matter).
23 is not in the sequence because both of its digits are prime.
MATHEMATICA
Select[Prime[Range[150]], Not[PrimeQ[Min[IntegerDigits[#]]]] &] (* Alonso del Arte, Mar 28 2014, based on Harvey P. Dale's program for A155053 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
EXTENSIONS
Entries checked by R. J. Mathar, Mar 29 2010
STATUS
approved