A085556 Numbers that have exactly as many prime digits as nonprime digits.

12, 13, 15, 17, 20, 21, 24, 26, 28, 29, 30, 31, 34, 36, 38, 39, 42, 43, 45, 47, 50, 51, 54, 56, 58, 59, 62, 63, 65, 67, 70, 71, 74, 76, 78, 79, 82, 83, 85, 87, 92, 93, 95, 97, 1022, 1023, 1025, 1027, 1032, 1033, 1035, 1037, 1052, 1053, 1055, 1057, 1072, 1073, 1075

Offset

1,1

Links

Table of n, a(n) for n=1..59.

Mathematica

Select[Range[1200], Count[IntegerDigits[#], _?PrimeQ]== IntegerLength[#]/2&] (* Harvey P. Dale, Jun 02 2011 *)

Crossrefs

Cf. A085520.

Sequence in context: A076979 A365589 A085520 * A175225 A187234 A127354

Adjacent sequences: A085553 A085554 A085555 * A085557 A085558 A085559

Keyword

base,easy,nonn

Author

Jason Earls, Jul 04 2003

Status

approved