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Search: id:A052940
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| A052940 |
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a(0) = 1; for n > 0, 3*2^n - 1. |
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+0
7
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| 1, 5, 11, 23, 47, 95, 191, 383, 767, 1535, 3071, 6143, 12287, 24575, 49151, 98303, 196607, 393215, 786431, 1572863, 3145727, 6291455, 12582911, 25165823, 50331647, 100663295, 201326591, 402653183, 805306367, 1610612735
(list; graph; listen)
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OFFSET
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0,2
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COMMENT
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A simple regular expression.
a(n) = A107909(A023548(n+1)) for n>1. - Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), May 28 2005
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LINKS
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INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 931
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FORMULA
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G.f.: -(-2*x+2*x^2-1)/(-1+2*x)/(-1+x)
Recurrence: {a(0)=1, -2*a(n)+a(n+1)-1, a(1)=5, a(2)=11}
Binomial transform of 3-0^n-(-1)^n=(1, 4, 2, 4, 2, 4, 2, .......). - Paul Barry (pbarry(AT)wit.ie), Jun 30 2003
Row sums of triangle A134060 - Gary W. Adamson (qntmpkt(AT)yahoo.com), Oct 05 2007
Equals row sums of triangle A140182 - Gary W. Adamson (qntmpkt(AT)yahoo.com), May 11 2008
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MAPLE
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spec := [S, {S=Prod(Sequence(Union(Z, Z)), Union(Sequence(Z), Z, Z))}, unlabeled ]: seq(combstruct[count ](spec, size=n), n=0..20);
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CROSSREFS
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Apart from initial terms, same as A055010 and A083329.
Cf. A134060.
Cf. A140182.
Sequence in context: A118439 A156109 A107010 this_sequence A102444 A132177 A046138
Adjacent sequences: A052937 A052938 A052939 this_sequence A052941 A052942 A052943
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KEYWORD
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easy,nonn
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AUTHOR
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encyclopedia(AT)pommard.inria.fr, Jan 25 2000
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EXTENSIONS
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More terms from James A. Sellers (sellersj(AT)math.psu.edu), Jun 08 2000
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