A117113 - OEIS

%I #9 Jan 14 2026 10:38:41

%S 1,2,4,3,3,2,4,4,2,1,4,2,5,3,2,2,4,3,2,3,3,2,4,3,3,2,4,4,2,2,3,2,4,3,

%T 3,2,4,4,2,2,3,2,4,3,3,2,4,4,2,1,3,2,4,3,3,2,4,4,2,2,3,2,4,3,3,2,4,4,

%U 2,2,3,2,4,3,3,2,4,4,2,2,3,2,4,3,3,2,4,4

%N Number of letters not in common with the number before.

%H Michael S. Branicky, <a href="/A117113/b117113.txt">Table of n, a(n) for n = 1..10000</a>

%e a(1)=1 from oNe & zErO, a(2)=2 from TWo & One, a(3)=4 from tHREE & Two, a(8)=4 from eIGHT & sEven, etc.

%e a(20)=3 from tWenTY & nineTEeN.

%o (Python)

%o from collections import Counter

%o from num2words import num2words

%o def n2w(n): return "".join(c for c in num2words(n).replace(" and", "") if c.isalpha())

%o def a(n): return (Counter(n2w(n)) - Counter(n2w(n-1))).total()

%o print([a(n) for n in range(1, 103)]) # _Michael S. Branicky_, Jan 13 2026

%Y Cf. A005589, A109382, A116531.

%K nonn,word

%O 1,2

%A _Rodolfo Kurchan_, Apr 18 2006

%E Offset, a(1) and a(20) corrected and a(24) onward from _Michael S. Branicky_, Jan 13 2026