A152889 Periodic sequence [1,0,4,0,0] of period 5.
1, 0, 4, 0, 0, 1, 0, 4, 0, 0, 1, 0, 4, 0, 0, 1, 0, 4, 0, 0, 1, 0, 4, 0, 0, 1, 0, 4, 0, 0, 1, 0, 4, 0, 0, 1, 0, 4, 0, 0, 1, 0, 4, 0, 0, 1, 0, 4, 0, 0, 1, 0, 4, 0, 0, 1, 0, 4, 0, 0, 1, 0, 4, 0, 0, 1, 0, 4, 0, 0, 1, 0, 4, 0, 0, 1, 0, 4, 0, 0, 1, 0, 4, 0, 0, 1, 0, 4, 0, 0, 1, 0, 4, 0, 0, 1, 0, 4, 0, 0, 1, 0, 4, 0, 0
Offset: 0
Links
- Index entries for linear recurrences with constant coefficients, signature (0,0,0,0,1).
Crossrefs
Cf. A026048.
Formula
a(n+5) = a(n) with a(0) = 1, a(2) = a(3) = a(4) = 0 and a(2) = 4.
O.g.f: (1+4z^2)/(1-z^5).
a(n) = 1-2/5*5^(1/2)*cos(2*n*Pi/5)+2/5*2^(1/2)*(5-5^(1/2))^(1/2)*sin(2*n*Pi/5) + 2/5*5^(1/2)*cos(4*n*Pi/5)-2/5*2^(1/2)*(5+5^(1/2))^(1/2)*sin(4*n*Pi/5).
Extensions
More terms from Philippe Deléham, Dec 29 2008