The Riddle
I am a sequence that starts with one, then three, then six, and ends at last. What number am I known as?
Related snips
Riddle
what-sequence-counts-without-numbers-starts-at-one-yet
i-start-with-one-then-two-then-three-and-so-on-without
i-can-measure-the-width-of-a-smile-or-the-length-of-a
i-can-be-heavy-or-light-but-youll-never-see-me-with
i-start-at-2-then-double-each-time-im-under-40-and-end