A154315 - OEIS

%I #8 Feb 06 2019 23:49:07

%S 1,5,8,10,14,15,19,23,27,28,38,39,43,46,47,50,56,61,70,77,83,85,92,97,

%T 100,104,112,113,115,120,126,127,135,136,143,144,146,149,155,156,157,

%U 158,161,163,166,167,170,173,175,177,183,184,185,189,192,195,201,208

%N Numbers k such that the number of prime digits in prime(k) equals the number of even digits in prime(k).

%p From _R. J. Mathar_, May 01 2010: (Start)

%p noPrimDgs := proc(n) a := 0 ; for d in convert(n,base,10) do if d in {2,3,5,7} then a := a+1 ; end if; end do; a ; end proc:

%p noEvDgs := proc(n) a := 0 ; for d in convert(n,base,10) do if type(d ,'even') then a := a+1 ; end if; end do; a ; end proc:

%p for n from 1 to 300 do p := ithprime(n) ; if noPrimDgs(p) = noEvDgs(p) then printf("%d,",n) ; end if; end do: (End)

%K nonn,base,less

%O 1,2

%A _Juri-Stepan Gerasimov_, Jan 15 2009

%E Corrected(8, 23 inserted, 26 replaced by 27, 29 by 28, 97 inserted ...) by _R. J. Mathar_, May 01 2010