Voozh

A142702

Period 4: repeat [5, 2, 5, 8].

5, 2, 5, 8, 5, 2, 5, 8, 5, 2, 5, 8, 5, 2, 5, 8, 5, 2, 5, 8, 5, 2, 5, 8, 5, 2, 5, 8, 5, 2, 5, 8, 5, 2, 5, 8, 5, 2, 5, 8, 5, 2, 5, 8, 5, 2, 5, 8, 5, 2, 5, 8, 5, 2, 5, 8, 5, 2, 5, 8, 5, 2, 5, 8, 5, 2, 5, 8, 5, 2, 5, 8, 5, 2, 5, 8, 5, 2, 5, 8, 5, 2, 5, 8

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

From Balmer spectrum of hydrogen.

LINKS

Table of n, a(n) for n=1..84.

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

FORMULA

a(n) = 5+3*cos(n*Pi/2). [From PARI program of Lafont, Aug 30 2009].

G.f.: ( 5-3*x+8*x^2 ) / ( (1-x)*(1+x^2) ). - R. J. Mathar, Apr 02 2011

a(n) = a(n-1) - a(n-2) + a(n-3) for n>3. - Wesley Ivan Hurt, Jul 08 2016