OFFSET
1,1
COMMENTS
Counts the distinct permutations of letters of the words 'one', 'two', 'three' etc.
EXAMPLE
For n = 1, a(1) = anagrams of 'one': 3! = 6.
For n = 9, a(9) = anagrams of 'nine' = 4! / 2! due to four letters but the letter 'n' occurring twice.
MATHEMATICA
a[n_] := Multinomial @@ Tally[Characters[StringReplace[IntegerName[n, "Words"], {"\[Hyphen]" -> "", " " -> "", ", " -> ""}]]][[;; , 2]]; Array[a, 50] (* Amiram Eldar, Nov 22 2018 *)
CROSSREFS
KEYWORD
nonn,word
AUTHOR
Anthony Clohesy, Nov 22 2018
EXTENSIONS
More terms from Amiram Eldar, Nov 22 2018
STATUS
approved