OFFSET
1,1
PROG
(PARI) x=0; n=-1; for(k=1, 9, z=n; while(1, n++; x=x+k*10^n; if(ispseudoprime(x), print(z=n-z); break))) \\ Dmitry Petukhov, Oct 15 2017
CROSSREFS
KEYWORD
base,more,nonn
AUTHOR
Amarnath Murthy, Sep 21 2003
EXTENSIONS
a(8) from David Wasserman, Jul 01 2005
a(9) from Dmitry Petukhov, Oct 15 2017
STATUS
approved