OFFSET
1,1
COMMENTS
Conjecture: there is an infinity of primes in A071998.
PROG
(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) }
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Cino Hilliard, Sep 08 2003
STATUS
approved