It looks like that never occurs for Helvetica (A316600) due to the absence of kerning. However, with Arial (A316599) the description notes:

> a(29368) = 111111 is a first notable anomaly, because its bounding box width of 2675 lies between those of a(29367) = 49115, with bounding box width 2655, and a(29369) = 70002, with bounding box width 2681.

According to the wiki [0], "This is a less interesting sequence and is less likely to be the one you were looking for."

Confusingly, "more" means "please add more terms"...

[0] https://oeis.org/wiki/Keywords