A154981 Primes with nonprime smallest digit.

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

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

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

Cf. A019546, A020457, A141468.

Sequence in context: A267277 A155071 A003626 * A092912 A092911 A062634

Adjacent sequences: A154978 A154979 A154980 * A154982 A154983 A154984

Keyword

nonn,base

Author

Juri-Stepan Gerasimov, Jan 19 2009

Extensions

Entries checked by R. J. Mathar, Mar 29 2010

Status

approved