A069575 Numbers k >= 4 such that k contains the digit 0 in no base b with 2 < b < k.

4, 5, 7, 13, 23, 43, 157, 619

Offset: 1

Author

Naohiro Nomoto, Apr 18 2002

Keywords

• base
• nonn
• more

Comments

Probably finite.

The next term (if it exists) is > 10000000. - Larry Reeves (larryr(AT)acm.org), Oct 12 2003

The next term (if it exists) is > 100000000. - Michel Marcus, Jul 14 2013

The next term (if it exists) is > 10^400. - Nathan Fox, Mar 09 2016

Every term in this sequence other than 4 is prime. - Nathan Fox, Mar 09 2016

No more terms through 10^5000. - Jon E. Schoenfield, Oct 13 2018

Programs

PARI

isok(n) = {for (b=3, n-1, digs = digits(n, b); for (j=1, #digs, if (digs[j] == 0, return (0)););); return (1);} \\ Michel Marcus, Jul 14 2013

Extensions

Corrected by Larry Reeves (larryr(AT)acm.org), Oct 12 2003