A083808 Smallest prime == 1 (mod n-th unary number U(n) = (10^n-1)/9).

2, 23, 223, 24443, 199999, 666667, 19999999, 22222223, 666666667, 44444444441, 22222222223, 2444444444443, 17777777777777, 88888888888889, 1333333333333333, 64444444444444439, 88888888888888889

Offset

1,1

Links

Table of n, a(n) for n=1..17.

Example

a(4) = 24443 ==1 (mod 1111).

Maple

with(numtheory): for n from 1 to 30 do u := (10^n-1)/9: for j from u+1 to 1000*u+1 by u do if isprime(j) then printf(`%d, `, j); break; fi: od:od:

Crossrefs

Cf. A000042.

Sequence in context: A069629 A069614 A036937 * A252016 A037750 A037631

Adjacent sequences: A083805 A083806 A083807 * A083809 A083810 A083811

Keyword

base,nonn

Author

Amarnath Murthy and Meenakshi Srikanth (menakan_s(AT)yahoo.com), May 08 2003

Extensions

Corrected and extended by James A. Sellers, May 19, 2003

Status

approved