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A152890
Periodic sequence [4,1,4,0,1] of period 5
2
4, 1, 4, 0, 1, 4, 1, 4, 0, 1, 4, 1, 4, 0, 1, 4, 1, 4, 0, 1, 4, 1, 4, 0, 1, 4, 1, 4, 0, 1, 4, 1, 4, 0, 1, 4, 1, 4, 0, 1, 4, 1, 4, 0, 1, 4, 1, 4, 0, 1, 4, 1, 4, 0, 1
OFFSET
0,1
FORMULA
a(n+5) = a(n).
G.f: (4+z+4*z^2+z^4)/(1-z^5).
a(n) = 2+(-1/5*5^(1/2)+1)*cos(2*n*Pi/5)+(2/5*2^(1/2)*(5-5^(1/2))^(1/2))*sin(2*n*Pi/5)+(1/5*5^(1/2)+1)*cos(4*n*Pi/5)+(-2/5*2^(1/2)*(5+5^(1/2))^(1/2))*sin(4*n*Pi/5)
CROSSREFS
Cf. A026051.
Sequence in context: A064221 A229672 A298568 * A143354 A324026 A171539
KEYWORD
easy,nonn,less
AUTHOR
Richard Choulet, Dec 14 2008
STATUS
approved