A084104 A period 6 sequence.

1, 4, 7, 7, 4, 1, 1, 4, 7, 7, 4, 1, 1, 4, 7, 7, 4, 1, 1, 4, 7, 7, 4, 1, 1, 4, 7, 7, 4, 1, 1, 4, 7, 7, 4, 1, 1, 4, 7, 7, 4, 1, 1, 4, 7, 7, 4, 1, 1, 4, 7, 7, 4, 1, 1, 4, 7, 7, 4, 1, 1, 4, 7, 7, 4, 1, 1, 4, 7, 7, 4, 1, 1, 4, 7, 7, 4, 1, 1, 4, 7, 7, 4, 1, 1, 4, 7, 7, 4, 1, 1, 4, 7, 7, 4, 1, 1, 4, 7, 7, 4, 1, 1, 4, 7

Offset: 0

Author

Paul Barry, May 15 2003

Keywords

• easy
• nonn

Comments

Partial sums of A084103.

Links

• Index entries for linear recurrences with constant coefficients, signature (2,-2,1).

Crossrefs

Cf. A084101, A007877.

Programs

PARI

{a(n)=[1, 4, 7, 7, 4, 1][n%6+1]}

PARI

a(n)=2*sqrt(3)*sin((n+5)*Pi/3)+4 \\ Jaume Oliver Lafont, Aug 27 2009

Formula

Euler transform of length 6 sequence [ 4, -3, -1, 0, 0, 1]. - Michael Somos, Nov 07 2006

G.f.: (1+x)^3/((1-x)(1+x^3)).

G.f.:(1+x)^2/((1-x)*(1-x+x^2)). - Jaume Oliver Lafont, Aug 27 2009