A006944 Number of letters in the n-th ordinal number (in American English). (Formerly M3744)

5, 6, 5, 6, 5, 5, 7, 6, 5, 5, 8, 7, 10, 10, 9, 9, 11, 10, 10, 9, 11, 12, 11, 12, 11, 11, 13, 12, 11, 9, 11, 12, 11, 12, 11, 11, 13, 12, 11, 8, 10, 11, 10, 11, 10, 10, 12, 11, 10, 8, 10, 11, 10, 11, 10, 10, 12, 11, 10, 8, 10, 11, 10, 11, 10, 10, 12, 11, 10, 10, 12, 13, 12, 13, 12, 12

Offset

1,1

Comments

a(0) is ambiguous (see Wikipedia: English numerals link). It is either 6 or 7 depending on whether the word used is 'zeroth' or 'noughth'. - Jon Perry, Nov 01 2014

The ordinal numbers 101st, 102nd, etc., are commonly spoken as "one hundred and first," "one hundred and second," etc., with the word "and" following the word "hundred." The more concise wordings "one hundred first," "one hundred second," etc. (without the word "and") are recommended by numerous authoritative reference works on American English, including the AP Style Guide and the U.S. Government Printing Office Style Manual. The American convention of omitting the "and" is followed in the b-file. - Jon E. Schoenfield, Nov 04 2014

References

Netnews group rec.puzzles, Frequently Asked Questions (FAQ) file (Science Section).

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

Jon E. Schoenfield, Table of n, a(n) for n = 1..1000

Associated Press, Stylebook

U.S. Government Printing Office, Style Manual 2008

Wikipedia, 101

Wikipedia, English numerals

Wikipedia, Ordinal numbers

Index entries for sequences related to number of letters in n

Example

"First" has 5 letters, so a(1)=5.
Hyphens and spaces are not counted, so, e.g., a(21)=11 ("twenty-first") and a(100)=12 ("one hundredth").

Prog

(Python)
from num2words import num2words
def a(n): return sum(1 for c in num2words(n, to='ordinal').replace(" and", "") if c.isalpha())
print([a(n) for n in range(1, 77)]) # Michael S. Branicky, Aug 08 2021 edited Jul 12 2022

Crossrefs

Cf. A005589.

Cf. A196278 (analog for French), A006969 (variant for French counting spaces and hyphens).

Sequence in context: A198742 A106704 A127205 * A010717 A046603 A139396

Adjacent sequences: A006941 A006942 A006943 * A006945 A006946 A006947

Keyword

nonn,word,nice,easy

Author

N. J. A. Sloane

Extensions

More terms from Jon E. Schoenfield, Aug 13 2007

Status

approved