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A371510
Number of swaps needed to bubble-sort the US English name of n.
1
4, 3, 2, 8, 1, 3, 1, 5, 2, 4, 2, 4, 9, 16, 16, 10, 13, 17, 11, 13, 5, 21, 14, 34, 21, 25, 16, 30, 29, 27, 3, 20, 11, 32, 18, 23, 12, 28, 27, 25, 0, 15, 7, 25, 11, 17, 8, 22, 20, 21, 1, 13, 7, 25, 10, 15, 7, 21, 17, 16, 2, 18, 12, 31, 18, 21, 11, 26, 25, 23, 6, 22, 15, 35, 22, 25, 16, 29, 30, 28, 2, 14, 8, 26, 13, 18, 8, 22, 19, 17, 4, 16, 10, 30, 15, 22, 12, 24, 26, 21, 28
OFFSET
0,1
COMMENTS
No swaps involve hyphens or spaces.
LINKS
Eric Angelini and Nicolas Graner, More bubble sorting, personal blog, March 2024.
EXAMPLE
For n=0, "zero" requires a(0) = 4 swaps of adjacent letters to reach ascending alphabetical order: ZERO-->EZRO-EZOR-EOZR-EORZ.
PROG
(Python)
from num2words import num2words
def a(n):
s = [c for c in num2words(n).replace(" and", "") if c.isalpha()]
L, c, swap = list(s), 0, True
while swap:
swap = False
for i in range(len(L)-1):
if L[i] > L[i+1]:
L[i], L[i+1], c, swap = L[i+1], L[i], c+1, True
return c
print([a(n) for n in range(101)]) # Michael S. Branicky, Mar 25 2024
CROSSREFS
Cf. A371478 (fixed points).
Sequence in context: A307648 A067016 A022295 * A258415 A132668 A018866
KEYWORD
base,nonn,word
AUTHOR
Eric Angelini and Nicolas Graner, Mar 25 2024
STATUS
approved