1,1

Complement of A097683.

Numbers k such that (10^n + 17)/9 is composite (see A098406).

Table of n, a(n) for n=1..71.

(PARI) isok(n) = ! isprime((10^n + 17)/9); \\ Michel Marcus, Jul 27 2017

Cf. A098406, A105433.

Sequence in context: A225551 A247359 A305415 * A324704 A203168 A284820

Adjacent sequences: A105429 A105430 A105431 * A105433 A105434 A105435

nonn,base

Lekraj Beedassy, Apr 08 2005

approved