OFFSET
1,2
COMMENTS
a(n+1) = le nombre des lettres dans a(n), a(1) = 1 (in French).
The English (1, 3, 5, 4, 4, 4, ...) and German (1, 4, 4, 4, ...) versions are less interesting.
Decimal expansion of 13847/11110 = 1.24635463546354635... - Eric Angelini, Sep 17 2006; corrected by Elmo R. Oliveira, Jun 29 2024
LINKS
Index entries for linear recurrences with constant coefficients, signature (0,0,0,1).
FORMULA
From Elmo R. Oliveira, Jun 29 2024: (Start)
G.f.: x*(1+2*x+4*x^2+6*x^3+2*x^4+3*x^5)/(1-x^4).
a(n) = a(n-4) for n > 6. (End)
EXAMPLE
Un, deux, quatre, six, trois, cinq, quatre, ...
UN (2 letters), DEUX (4 letters), QUATRE (6 letters), SIX (3 letters), TROIS (5 letters), CINQ (4 letters), QUATRE (6 letters), ...
MATHEMATICA
PadRight[{1, 2}, 100, {3, 5, 4, 6}] (* Paolo Xausa, Jul 08 2026 *)
CROSSREFS
KEYWORD
nonn,word,easy
AUTHOR
N. J. A. Sloane, Jun 14 2001
EXTENSIONS
Edited by N. J. A. Sloane at the suggestion of Andrew S. Plewe, Jun 08 2007
STATUS
approved