A061504 a(1) = 1; for n>1, a(n) = numbers of letters in French name for a(n-1).

1, 2, 4, 6, 3, 5, 4, 6, 3, 5, 4, 6, 3, 5, 4, 6, 3, 5, 4, 6, 3, 5, 4, 6, 3, 5, 4, 6, 3, 5, 4, 6, 3, 5, 4, 6, 3, 5, 4, 6, 3, 5, 4, 6, 3, 5, 4, 6, 3, 5, 4, 6, 3, 5, 4, 6, 3, 5, 4, 6, 3, 5, 4, 6, 3, 5, 4, 6, 3, 5, 4, 6, 3, 5, 4, 6, 3, 5, 4, 6, 3, 5, 4, 6, 3, 5, 4, 6, 3, 5, 4, 6, 3, 5, 4, 6, 3, 5, 4

Offset: 1

Author

N. J. A. Sloane, Jun 14 2001

Keywords

• nonn
• word
• easy

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

Examples

			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), ...
		

Links

• Index entries for linear recurrences with constant coefficients, signature (0,0,0,1).

Crossrefs

Cf. A007005 (number of letters).

Cf. A000655 (English), A101432 (Spanish), A328263 (Polish).

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)

Extensions

Edited by N. J. A. Sloane at the suggestion of Andrew S. Plewe, Jun 08 2007