A177499 Period 4: repeat [1, 16, 4, 16].

1, 16, 4, 16, 1, 16, 4, 16, 1, 16, 4, 16, 1, 16, 4, 16, 1, 16, 4, 16, 1, 16, 4, 16, 1, 16, 4, 16, 1, 16, 4, 16, 1, 16, 4, 16, 1, 16, 4, 16, 1, 16, 4, 16, 1, 16, 4, 16, 1, 16, 4, 16, 1, 16, 4, 16, 1, 16, 4, 16, 1, 16, 4, 16, 1, 16, 4, 16, 1, 16, 4, 16, 1, 16, 4, 16, 1, 16, 4, 16, 1, 16, 4, 16

Offset: 0

Author

Paul Curtz, May 10 2010

Keywords

• nonn
• easy

Comments

From Klaus Brockhaus, May 14 2010: (Start)

Interleaving of A000012, A010855, A010709 and A010855.

Continued fraction expansion of (44+sqrt(2442))/88. (End)

Links

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

Crossrefs

Cf. A010674, A177838. [Klaus Brockhaus, May 14 2010]

Cf. A000012, A010709, A010855, A176895.

Programs

Magma

&cat[[1, 16, 4, 16]^^26]; // Klaus Brockhaus, May 14 2010

Maple

seq(op([1, 16, 4, 16]), n=0..50); # Wesley Ivan Hurt, Jul 09 2016

Mathematica

Table[{1, 16, 4, 16}, {21}] // Flatten (* Jean-François Alcover, May 24 2013 *)

Formula

From Klaus Brockhaus, May 14 2010: (Start)

a(n+2) - a(n) = A010674(n).

a(n) = a(n-4) for n > 3.

G.f.: (1+16*x+4*x^2+16*x^3)/(1-x^4). (End)

a(n) = A176895(n)^2. - Paul Curtz, Mar 21 2011

a(n) = (37 - 6*cos(n*Pi/2) - 27*cos(n*Pi) - 27*I*sin(n*Pi))/4. - Wesley Ivan Hurt, Jul 09 2016