OFFSET
1,1
COMMENTS
In US English, "101" is written as "one hundred one".
From Michael S. Branicky, Oct 24 2020 (Start)
The sequence counts vowels by counting the instances of the letters 'a', 'e', 'i', 'o', 'u', and 'y' (see Example). If 'y' were not included, then a(5) = 102 ("OnE hUndrEd twO") is the first among subsequent value changes.
In extending the sequence to large numbers, the "American system" (Weisstein link), also known as the "short scale" (Wikipedia link), was used. Also, the common written form is adopted ("one thousand one hundred seventeen" not "eleven hundred seventeen"; Wilson link).
(End)
LINKS
Eric Weisstein's World of Mathematics, Large Number
Wikipedia, Names of Large Numbers
Wiktionary, one hundred one (US)
Wiktionary, one hundred and one (UK)
EXAMPLE
"twO" has 1 vowel, "thrEE" has 2, "ElEvEn" has 3, "fOUrtEEn" has 4, "sEvEntY-OnE" has 5, "OnE hUndrEd OnE" has 6, "OnE hUndrEd ElEvEn" has 7.
PROG
(Python)
from num2words import num2words
def A158353upto(n):
i, ans = 1, []
for k in range(1, n+1):
while sum(1 for c in num2words(i).replace(' and ', '') if c in "aeiouy") != k:
i += 1
ans.append(i)
return ans
print(A158353upto(20)) # Michael S. Branicky, Oct 23 2020
CROSSREFS
KEYWORD
nonn,word
AUTHOR
Rodolfo Kurchan, Mar 16 2009
EXTENSIONS
Edited by Jon E. Schoenfield, Sep 29 2018
a(9) and beyond from Michael S. Branicky, Oct 23 2020
STATUS
approved