A000655 - OEIS

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

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OFFSET

1,2

COMMENTS

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

LINKS

Table of n, a(n) for n=1..80.

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

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

EXAMPLE

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

MATHEMATICA

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

CROSSREFS

Cf. A005589 (number of letters).

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

Sequence in context: A081361 A195132 A086181 * A130532 A019707 A197825

Adjacent sequences: A000652 A000653 A000654 * A000656 A000657 A000658

KEYWORD

nonn,word,easy

AUTHOR

N. J. A. Sloane

STATUS

approved