A043292 Numbers that divide 10^k + 1 for some k.

1, 2, 7, 11, 13, 17, 19, 23, 29, 47, 49, 59, 61, 73, 77, 89, 91, 97, 101, 103, 109, 113, 121, 127, 131, 133, 137, 139, 143, 149, 157, 161, 167, 169, 179, 181, 193, 197, 209, 211, 223, 229, 233, 241, 247, 251, 253, 257, 263, 269, 281, 289, 293, 299, 313, 329

Offset: 1

Author

Vladeta Jovovic, Apr 04 2002

Keywords

• nonn

Links

• Robert Israel, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A014657, A069531.

Odd primes in this sequence are A028416.

Programs

Maple

filter:= n -> traperror(NumberTheory:-ModularLog(-1,10,n)) <> "no solutions exist":
filter(2):= true:
select(filter, [$1..500]); # Robert Israel, Feb 11 2023