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A123344 Expansion of (1+3x)/(1+2x). 2
1, 1, -2, 4, -8, 16, -32, 64, -128, 256, -512, 1024, -2048, 4096, -8192, 16384, -32768, 65536, -131072, 262144, -524288, 1048576, -2097152, 4194304, -8388608, 16777216, -33554432, 67108864, -134217728, 268435456, -536870912, 1073741824, -2147483648 (list; graph; refs; listen; history; internal format)
OFFSET

0,3

COMMENTS

Inverse binomial transform of A000034 . Hankel transform is [1,-3,0,0,0,0,0,0,0,0,...]

FORMULA

a(0)=1, a(n)=(-2)^(n-1) for n>0 .G.f.: (1+3x)/(1+2x).

MAPLE

a:=n->mul(-2, k=0..n): seq(a(n), n=-2..30); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Jan 22 2008

CROSSREFS

Cf. A011782(unsigned version).

Sequence in context: A034008 * A141531 A166444 A084633 A122803 A000079

Adjacent sequences:  A123341 A123342 A123343 * A123345 A123346 A123347

KEYWORD

easy,sign

AUTHOR

Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Oct 11 2006

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Last modified February 17 16:49 EST 2012. Contains 206058 sequences.