A288351 Number of strings of n digits from 1...9 such that no formula using the single digits in the given order exists that evaluates to 0.

9, 72, 455, 1500, 1014, 181, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0

Offset

1,1

Comments

For definitions and comments see A288350.

It is conjectured that a(n)=0 for n>=8.

The conjecture is true, as shown in the corresponding comment in A288350. - Hugo Pfoertner, Jun 09 2017

Links

Table of n, a(n) for n=1..78.

Example

a(1)=9 because 1...9 /=0. a(2)=72, because only the 9 numbers 11, 22, ..., 99 of the 81 two-digit strings can represent 0.

Crossrefs

Cf. A288350, A288352, A288353, A288354, A288355, A288356.

Sequence in context: A070823 A073988 A005778 * A319892 A319873 A110396

Adjacent sequences: A288348 A288349 A288350 * A288352 A288353 A288354

Keyword

nonn

Author

Hugo Pfoertner, Jun 08 2017

Status

approved