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Search: id:A103456
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| 1, 9, 99, 999, 9999, 99999, 999999, 9999999, 99999999, 999999999, 9999999999, 99999999999, 999999999999, 9999999999999, 99999999999999, 999999999999999, 9999999999999999, 99999999999999999, 999999999999999999
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OFFSET
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0,2
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COMMENT
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A transform of 10^n under the matrix A103452.
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FORMULA
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G.f.: (1-2x+10x^2)/((1-x)(1-10x)); a(n)=sum{k=0..n, A103452(n, k)10^k}; a(n)=sum{k=0..n, (2*0^(n-k)-1)*0^(k(n-k))10^k}.
a(n)=A002283(n), n>0. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 30 2008]
a(n)=10*a(n-1)+9-10*{C[2*(n-1),n-1] mod 2}, with a(0)=1 [From Paolo P. Lava (ppl(AT)spl.at), Jun 04 2009]
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CROSSREFS
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Sequence in context: A108908 A116260 A002283 this_sequence A155157 A015685 A051581
Adjacent sequences: A103453 A103454 A103455 this_sequence A103457 A103458 A103459
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KEYWORD
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easy,nonn
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AUTHOR
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Paul Barry (pbarry(AT)wit.ie), Feb 06 2005
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