|
|
A103443
|
|
Largest left-truncatable prime in base n (decimal expansion).
|
|
8
|
|
|
23, 4091, 7817, 4836525320399, 817337, 14005650767869, 1676456897, 357686312646216567629137, 2276005673, 13092430647736190817303130065827539, 812751503, 615419590422100474355767356763
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
3,1
|
|
LINKS
|
I. O. Angell, and H. J. Godwin, On Truncatable Primes Math. Comput. 31, 265-267, 1977. (See also Sloane link below)
|
|
PROG
|
(PARI) a(n)=my(v=primes(primepi(n-1)), u, t, b=1, best); while(#v, best=vecmax(v); b*=n; u=List(); for(i=1, #v, for(k=1, n-1, if(isprime(t=v[i]+k*b), listput(u, t)))); v=Vec(u)); best \\ Charles R Greathouse IV, Feb 05 2013
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,base
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|