OFFSET
1,1
COMMENTS
Nombres de caractères (lettres, espaces et tirets) des nombres ordinaux en français.
In contrast to A196278, hyphens and spaces are counted here. First differs at n = 17 (dix-septième). - Georg Fischer, Aug 07 2021
In French the final -s in "quatre-vingts", "deux cents", ... disappears when the ordinal suffix "-ième" is appended. (This is currently incorrectly handled in the Python module num2words.) Also, the trailing "-e" of numbers ending in "quatre", "onze" - "seize", "trente" - "soixante" disappears. Therefore, in all these cases the name of the ordinal has only 3 letters more than the name of the cardinal, viz. a(n) = A007005(n)+3. For numbers ending in "cinq", there appears an additional "u", whence a(n) = A007005(n)+5 in this case. - M. F. Hasler, Aug 08 2021
REFERENCES
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
FORMULA
a(n) = A007005(n) + e, where e = 4 except for n = 1 and when the French name of n ends in "cinq" (then e = 5), or when it ends in "-e" or "-ts" (then e = 3). - M. F. Hasler, Aug 08 2021
EXAMPLE
a(21) = # "vingt-et-unième" = 15, where # means length of the string.
a(50) = # "cinquantième" = 12.
a(80) = # "quatre-vingtième": the '-s' disappears from "quatre-vingts".
a(200) = # "deux-centième": the '-s' disappears from "deux cents".
PROG
(PARI) apply( {A006969(n, t=French(n))=#t+if(n==1||"nq"==t=Strchr(Vecsmall(t)[-2..-1]), 5, "ts"==t || Vec(t)[2]=="e", 3, 4)}, [1..55]) \\ See A007005 for French(). - M. F. Hasler, Aug 08 2021
CROSSREFS
KEYWORD
nonn,word
AUTHOR
EXTENSIONS
Edited by M. F. Hasler, Aug 08 2021
STATUS
approved