A117076 Prime numbers with more even digits than odd digits.

2, 223, 227, 229, 241, 263, 269, 281, 283, 401, 409, 421, 443, 449, 461, 463, 467, 487, 601, 607, 641, 643, 647, 661, 683, 809, 821, 823, 827, 829, 863, 881, 883, 887, 2003, 2027, 2029, 2063, 2069, 2081, 2083, 2087, 2089, 2203, 2207, 2221, 2243, 2267, 2269

Offset

1,1

Comments

If a prime number's even digits are to outnumber its odd digits, it may not have two digits (as its last digit must be odd.) Neither may it begin with an odd digit if it has three or four digits. The smallest member of this sequence to begin with an odd digit is 10007.

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Example

64969 is a member of this sequence as it is a prime with 3 even and only two odd digits. The primes on either side of it - 64951 and 64997 - are both non-members.

Mathematica

Select[Prime[Range[1000]], Sum[DigitCount[ # ][[2i - 1]], {i, 1, 5}] < Sum[DigitCount[ # ][[2i]], {i, 1, 5}] &] (* Stefan Steinerberger, Apr 18 2006 *)
metoQ[n_]:=Module[{idn=IntegerDigits[n]}, Count[idn, _?EvenQ]>Count[idn, _?OddQ]]; Select[Prime[Range[350]], metoQ] (* Harvey P. Dale, Oct 10 2018 *)

Prog

(PARI) select( {is_A117076(n)=isprime(n)&&vecsum(n=digits(n)%2)*2<#n}, primes(500)) \\ M. F. Hasler, Jul 03 2022

Crossrefs

Sequence in context: A307511 A293945 A078276 * A132936 A110715 A242835

Adjacent sequences: A117073 A117074 A117075 * A117077 A117078 A117079

Keyword

base,easy,nonn

Author

Andy Edwards, Apr 18 2006

Extensions

More terms from Stefan Steinerberger, Apr 18 2006

Status

approved