1,1

Conjecture: there is an infinity of primes in A071998.

(PARI) binofbin(n) = { c=0; for(x=0, n, b=binary(x); ln=length(b); z=Str(b[1]); for(j=2, ln, z=concat(Str(z), Str(b[j])); ); d = eval(z); b=binary(d); ln=length(b); z=Str(b[1]); for(j=2, ln, z=concat(Str(z), Str(b[j])); ); \ print1(z, ", ") if(isprime(eval(z)), print1(eval(z), ", "); c++) ); print(); print(c) }

Sequence in context: A070042 A109148 A077647 this_sequence A060087 A035613 A038449

Adjacent sequences: A086209 A086210 A086211 this_sequence A086213 A086214 A086215

base,nonn

Cino Hilliard (hillcino368(AT)gmail.com), Sep 08 2003