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A122958
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a(0)=1, a(n)=2-2^(n-1) for n>0.
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1
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1, 1, 0, -2, -6, -14, -30, -62, -126, -254, -510, -1022, -2046, -4094, -8190, -16382, -32766, -65534, -131070, -262142, -524286, -1048574, -2097150, -4194302, -8388606, -16777214, -33554430, -67108862, -134217726, -268435454
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,4
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COMMENTS
| Take square of A014217 (1,1,2,4,6) and successive differences: a(n) is principal diagonal (k-th term of k-th row). a(n) differences:0,-1,-2,-4,-8,-16,=-A131577. [From Paul Curtz (bpcrtz(AT)free.fr), Sep 26 2008]
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LINKS
| Vincenzo Librandi, Table of n, a(n) for n = 0..1000
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FORMULA
| a(0)=1, a(1)=1, a(2)=0, a(n)=3*a(n-1)-2*a(n-2) for n>2 . G.f. : (1-2*x-x^2)/(1-3*x+2*x^2) . a(n)=-A000918(n-1) for n>0.
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CROSSREFS
| Apart from signs, same as A000918.
Sequence in context: A072611 A192966 A000918 * A095121 A122959 A059076
Adjacent sequences: A122955 A122956 A122957 * A122959 A122960 A122961
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KEYWORD
| sign,easy
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AUTHOR
| Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Oct 26 2006
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EXTENSIONS
| Corrected a(22) by Vincenzo Librandi, Aug 11 2011
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