A117902 - OEIS

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A117902

Expansion of (1-x^2-2x^3)/(1-4x^3).

1, 0, -1, 2, 0, -4, 8, 0, -16, 32, 0, -64, 128, 0, -256, 512, 0, -1024, 2048, 0, -4096, 8192, 0, -16384, 32768, 0, -65536, 131072, 0, -262144, 524288, 0, -1048576, 2097152, 0, -4194304, 8388608, 0, -16777216, 33554432, 0, -67108864, 134217728, 0, -268435456, 536870912, 0, -1073741824 (list; graph; refs; listen; history; internal format)

	OFFSET	`0,4`
	COMMENTS	`Row sums of number triangle A117901.`
	FORMULA	`a(n)=0^n/2-2^(2n/3)(cos(2pin/3+pi/3)/6+sqrt(3)sin(2pin/3+pi/3)/6 -(2^(2/3)/12+2/3)cos(2pin/3)-432^(1/6)sin(2pin/3)/12+2^(2/3)/12-1/6)`
	CROSSREFS	`Sequence in context: A190791 A002885 A011121 * A021087 A120558 A120554` `Adjacent sequences: A117899 A117900 A117901 * A117903 A117904 A117905`
	KEYWORD	`easy,sign`
	AUTHOR	`Paul Barry (pbarry(AT)wit.ie), Apr 01 2006`

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Last modified February 17 04:58 EST 2012. Contains 205985 sequences.