OFFSET
1,2
COMMENTS
a(185) > 10^6, see link. Richard N. Smith, Jul 16 2019
LINKS
Richard N. Smith, Table of n, a(n) for n = 1..184
Karsten Bonath, Proth prime small bases least n
Richard N. Smith, Table of n, a(n) for n = 1..500 status
MATHEMATICA
f[n_] := Block[{k = 1}, While[ !PrimeQ[10*n^k + 1], k++ ]; k]]; f[1] = 1; Table[ f[n], {n, 1, 99}] (* Robert G. Wilson v, Oct 29 2003 *)
PROG
(PARI) a(n)=if((n%11==1 || n%33==32) && n>1, 0, for(k=1, 10^6, if(ispseudoprime(10*n^k+1), return(k)))) \\ Richard N. Smith, Jul 16 2019
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Ray Chandler, Oct 23 2003
STATUS
approved