A000655 a(n) = number of letters in a(n-1), a(1) = 1 (in English).

1, 3, 5, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn
• word
• easy

Comments

Decimal expansion of 1219/900. - Elmo R. Oliveira, May 05 2024

Examples

			One, three, five, four, four, four, ...
		

Links

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

Crossrefs

Cf. A005589 (number of letters).

Cf. A061504 (French), A101432 (Spanish), A328263 (Polish).

Programs

Mathematica

Nest[Append[#, StringLength@ IntegerName[#[[-1]], "Words"]] &, {1}, 105] (* Michael De Vlieger, Feb 17 2021 *)

Formula

a(n) = 4 for n > 3, with a(1) = 1, a(2) = 3 and a(3) = 5. - Wesley Ivan Hurt, Oct 03 2020

E.g.f.: - 4 - 3*x - (1/2)*x^2 + (1/6)*x^3 + 4*exp(x). - Alejandro J. Becerra Jr., Feb 17 2021

G.f.: x*(1+2*x+2*x^2-x^3)/(1-x). - Elmo R. Oliveira, Jun 25 2024