A095250 a(n) = 11111111... (n times) = (10^n-1)/9 reduced mod n.

0, 1, 0, 3, 1, 3, 1, 7, 0, 1, 1, 3, 1, 11, 6, 7, 1, 9, 1, 11, 6, 11, 1, 15, 11, 11, 0, 19, 1, 21, 1, 7, 12, 11, 16, 27, 1, 11, 33, 31, 1, 21, 1, 11, 36, 11, 1, 39, 36, 11, 9, 19, 1, 27, 1, 39, 54, 11, 1, 51, 1, 11, 27, 7, 61, 33, 1, 23, 42, 61, 1, 63, 1, 11, 36, 47, 23, 39, 1, 71, 0, 11, 1, 63

Offset

1,4

Comments

a(p) = 1 if p is a prime; a(3^k) = 0.

References

Amarnath Murthy, "On the divisors of Smarandache Unary Sequence", Smarandache Notions Journal, 1-2-3, vol. 11, 2000.

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Formula

a(n) = A002275(n) mod n.

Example

1111111 mod 7 = 1.

Mathematica

Table[Mod[FromDigits[PadRight[{}, n, 1]], n], {n, 90}] (* Harvey P. Dale, Jun 19 2022 *)

Prog

(PARI) a(n) = (10^n - 1)/9 % n; \\ Michel Marcus, Jul 03 2019

Crossrefs

Cf. A002275.

Sequence in context: A281113 A361519 A236757 * A135521 A344763 A176032

Adjacent sequences: A095247 A095248 A095249 * A095251 A095252 A095253

Keyword

nonn

Author

Amarnath Murthy, Jun 17 2004

Status

approved