A116531 Number of letters in common in the US English names for the numbers n and n+1.

2, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 4, 3, 5, 5, 5, 5, 5, 6, 3, 6, 7, 7, 7, 7, 7, 7, 7, 8, 4, 6, 7, 7, 7, 7, 7, 7, 7, 8, 3, 5, 6, 6, 6, 6, 6, 6, 6, 7, 4, 5, 6, 6, 6, 6, 6, 6, 6, 7, 3, 5, 6, 6, 6, 6, 6, 6, 6, 7, 5, 7, 8, 8, 8, 8, 8, 8, 8, 9, 4, 6, 7, 7, 7, 7, 7, 7, 7, 8, 6, 6, 7, 7, 7, 7, 7, 7, 7, 8, 4, 10, 11, 11

Offset

0,1

Links

Michael S. Branicky, Table of n, a(n) for n = 0..10000

Example

a(0)=2 from OnE and zErO, a(1)=1 from twO and One, a(2)=1 from Three and Two, a(7)=1 from Eight and sEven, etc.
a(101)=11 from ONEHUNDREDtwO and ONEHUNDREDOne.

Prog

(Python)
from collections import Counter
from num2words import num2words
def n2w(n): return "".join(c for c in num2words(n).replace(" and", "") if c.isalpha())
def a(n): return (Counter(n2w(n)) & Counter(n2w(n+1))).total()
print([a(n) for n in range(103)]) # Michael S. Branicky, Jan 13 2026

Crossrefs

Cf. A005589, A109382.

Sequence in context: A147753 A333355 A354523 * A375039 A101871 A101875

Adjacent sequences: A116528 A116529 A116530 * A116532 A116533 A116534

Keyword

nonn,word

Author

Rodolfo Kurchan, Mar 26 2006

Extensions

Corrected and edited by Robert G. Wilson v, Apr 06 2006

Status

approved