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A154981 Primes with nonprime smallest digit. 2

%I

%S 11,13,17,19,31,41,47,61,67,71,89,101,103,107,109,113,127,131,137,139,

%T 149,151,157,163,167,173,179,181,191,193,197,199,211,241,251,271,281,

%U 307,311,313,317,331,401,409,419,421,431,449,457,461,467,479,487,491

%N Primes with nonprime smallest digit.

%C Nonprime digits in base 10 are 0, 1, 4, 6, 8 and 9.

%H Vincenzo Librandi, <a href="/A154981/b154981.txt">Table of n, a(n) for n = 1..1000</a>

%e 17 is in the sequence because its smallest digit is 1, which is not prime.

%e 19 is in the sequence because its smallest digit is 1, which is not prime (neither is 9, for that matter).

%e 23 is not in the sequence because both of its digits are prime.

%t Select[Prime[Range[150]], Not[PrimeQ[Min[IntegerDigits[#]]]] &] (* _Alonso del Arte_, Mar 28 2014, based on _Harvey P. Dale_'s program for A155053 *)

%Y Cf. A019546, A020457, A141468.

%K nonn,base

%O 1,1

%A _Juri-Stepan Gerasimov_, Jan 19 2009

%E Entries checked by _R. J. Mathar_, Mar 29 2010

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Last modified May 23 03:01 EDT 2019. Contains 323507 sequences. (Running on oeis4.)