%I A088998
%S A088998 19,29,59,97,79,89,61,67,109,139,149,191,193,199,197,179,163,167,229,
%T A088998 239,293,263,269,349,359,397,379,389,367,409,419,439,449,491,499,479,
%U A088998 461,463,467,509,593,599,563,569,907,911,919,929,937,941,947,953,991
%N A088998 Flip 6,9 primes.
%C A088998 Surely these are infinite?
%F A088998 For digits d of n if d=6 make it 9 else if d=9 make it 6 and test for 
               prime()
%e A088998 76 -> 79 prime
%o A088998 (PARI) flip69pr(n) = { for(x=1,n, y=x; v=0; f=0; ln =length(Str(x)); 
               a = vector(ln); forstep(j=ln,1,-1, r = y%10; a[j]=r; if(r==6,a[j] 
               = 9; f=1); if(r==9,a[j] = 6; f=1); y = floor(y/10); ); forstep(j=ln,
               1,-1, v=v+a[j]*10^(ln-j) ); if(isprime(v) && f,print1(v",")); ) }
%Y A088998 Sequence in context: A141311 A090148 A136071 this_sequence A139886 A089724 
               A038542
%Y A088998 Adjacent sequences: A088995 A088996 A088997 this_sequence A088999 A089000 
               A089001
%K A088998 nonn
%O A088998 1,1
%A A088998 Cino Hilliard (hillcino368(AT)gmail.com), Nov 02 2003