212889600

Appears in sequences

• a(n) = (2*n+8)!!/8!!, related to A000165 (even double factorials).at n=7A051582
• Number of "ups" and "downs" in the permutations of [n] if either a previous counted "up" ("down") or a "void" precedes an "up" ("down") which then will be counted also.at n=9A120928