285

Number
$285$ (two hundred and eighty-five) is:


 * $3 \times 5 \times 19$


 * The $9$th square pyramidal number after $1, 5, 14, 30, 55, 91, 140, 204$:
 * $285 = 1 + 4 + 9 + 16 + 25 + 36 + 49 + 64 + 81 = \displaystyle \sum_{k \mathop = 1}^9 k^2 = \dfrac {9 \left({9 + 1}\right) \left({2 \times 9 + 1}\right)} 6$


 * The $53$rd lucky number:
 * $1, 3, 7, 9, 13, 15, 21, \ldots, 237, 241, 259, 261, 267, 273, 283, 285, \ldots$


 * The $16$th integer after $7, 13, 19, 35, 38, 41, 57, 65, 70, 125, 130, 190, 205, 223, 253$ the decimal representation of whose square can be split into two parts which are each themselves square:
 * $285^2 = 81 \, 225; 81 = 9^2, 225 = 15^2$


 * The $56$th positive integer $n$ such that no factorial of an integer can end with $n$ zeroes.

Also see



 * This sequence has not been continued on this site, as it is of limited importance. If anybody wishes to continue it, let them do so.
 * This sequence has not been continued on this site, as it is of limited importance. If anybody wishes to continue it, let them do so.