| ||||
|---|---|---|---|---|
| Cardinal | two hundred eighty | |||
| Ordinal | 280th (two hundred eightieth) | |||
| Factorization | 23 × 5 × 7 | |||
| Greek numeral | ΣΠ´ | |||
| Roman numeral | CCLXXX | |||
| Binary | 1000110002 | |||
| Ternary | 1011013 | |||
| Senary | 11446 | |||
| Octal | 4308 | |||
| Duodecimal | 1B412 | |||
| Hexadecimal | 11816 | |||
280 (two hundred [and] eighty) is the natural number after 279 and before 281.
In mathematics[edit]
The denominator of the eighth harmonic number,[1] 280 is an octagonal number.[2] 280 is the smallest octagonal number that is a half of another octagonal number.
There are 280 plane trees with ten nodes. As a consequence of this, 18 people around a round table can shake hands with each other in non-crossing ways, in 280 different ways (this includes rotations). [disputed – discuss]
Integers from 281 to 289[edit]
281[edit]
282[edit]
283[edit]
284[edit]
285[edit]
286[edit]
287[edit]
288[edit]
289[edit]
References[edit]
- ^ "Sloane's A002805 : Denominators of harmonic numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-28.
- ^ "Sloane's A000567 : Octagonal numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-28.
Well, that’s interesting to know that Psilotum nudum are known as whisk ferns. Psilotum nudum is the commoner species of the two. While the P. flaccidum is a rare species and is found in the tropical islands. Both the species are usually epiphytic in habit and grow upon tree ferns. These species may also be terrestrial and grow in humus or in the crevices of the rocks.
View the detailed Guide of Psilotum nudum: Detailed Study Of Psilotum Nudum (Whisk Fern), Classification, Anatomy, Reproduction