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A053655
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a(n)=(10^n-1)*(10^(2*n-1)-1)/81.
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0
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1, 1221, 1233321, 1234444321, 1234555554321, 1234566666654321, 1234567777777654321, 1234567888888887654321, 1234567899999999987654321, 1234567901111111110987654321, 1234567901222222222220987654321
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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REFERENCES
| W. Lietzmann, Sonderlinge im Reich der Zahlen, Ferd. Duemmlers Verlag Bonn, 1948, p. 30.
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EXAMPLE
| a(2)=11*111=1221; a(3)=111*11111=1233321; a(49=1111*1111111=1234444321.
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CROSSREFS
| Sequence in context: A015279 A179140 A091790 * A068262 A128655 A014488
Adjacent sequences: A053652 A053653 A053654 * A053656 A053657 A053658
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KEYWORD
| easy,nonn
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AUTHOR
| Klaus Strassburger (strass(AT)ddfi.uni-duesseldorf.de), Feb 17 2000
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