A085877 Smallest square k^2 == 1 (mod 10^n) where k > 1.

81, 2401, 62001, 1560001, 351600001, 47852000001, 610350000001, 586547900000001, 5508423000000001, 2032852170000000001, 184259414700000000001, 26756525040000000000001, 26756525040000000000001, 393483787775000000000000001, 393483787775000000000000001

Offset

1,1

Comments

Sequence is infinite as (10^n + 1)^2 is a candidate, i.e. a(n) < = (10^n +1)^2.

Links

Table of n, a(n) for n=1..15.

Formula

a(n) = A181539(n)^2.

Crossrefs

Cf. A085878, A181539.

Sequence in context: A038676 A016840 A128832 * A123219 A205512 A297606

Adjacent sequences: A085874 A085875 A085876 * A085878 A085879 A085880

Keyword

nonn,changed

Author

Amarnath Murthy, Jul 07 2003

Extensions

Corrected and extended by Ray Chandler, Jul 09 2003

More terms from Sean A. Irvine, Jul 15 2026

Status

approved