Where does “double factorial” come from?
double factorial (English) comes from English factorial, from English factor, from Middle French facteur, from Latin factor, from Latin faciō, from Latin -torium, from Latin -tōrius, from Latin -tor.
double factorial (English): For an odd integer, the result of multiplying all...
Definitions
- For an odd integer, the result of multiplying all...
Ancestry of “double factorial”, step by step
double factorial traces back through two separate lines of ancestry.
via English factorial
| Step | Language | Word | Meaning |
|---|---|---|---|
| 1 | English | factorial | The result of multiplying a given number of... |
| 2 | English | factor | A doer, maker; a person who does things for... |
| 3 | Middle French | facteur | — |
| 4 | Latin | factor | One who or which does or makes something; doer,... |
| 5 | Latin | faciō | to do |
| 6 | Latin | -torium | nominative neuter singular of -tōrius; accusative... |
| 7 | Latin | -tōrius | ory |
| 8 | Latin | -tor | -er |
| 9 | Proto-Italic | -tōr | Forms agent nouns to verb stems |
| 10 | Proto-Indo-European | -tōr | Derives agent nouns from verbs, denoting someone... |
| 11 | Proto-Indo-European | -tor-s | — |