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A007942
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Concatenation of sequence (n,n-1,..,2,1,2,..,n-1,n).
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1
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1, 212, 32123, 4321234, 543212345, 65432123456, 7654321234567, 876543212345678, 98765432123456789, 109876543212345678910, 1110987654321234567891011
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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COMMENTS
| Also called Smarandache mirror sequence.
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REFERENCES
| F. Smarandache, "Only Problems, not Solutions!", Xiquan Publ., Phoenix-Chicago, 1993
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LINKS
| M. L. Perez et al., eds., Smarandache Notions Journal
F. Smarandache, Only Problems, Not Solutions!
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FORMULA
| a(n+1)=n*10^{floor[1+log10(a(n))]+floor[1+log10(n)]}+a(n)*10^floor[1+log10(n)]+n, with a(1)=1 - Paolo P. Lava (paoloplava(AT)gmail.com), Jun 04 2008
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MAPLE
| P:=proc(n) local a, b, i; a:=1; b:=0; print(a); for i from 1 by 1 to n do b:=a; a:=(i+1)*10^(2+floor(evalf(log10(b), 10))+floor(evalf(log10(i+1), 10)))+b*10^(1+floor(evalf(log10(i+1), 10)))+i+1; print(a); od; end: P(100); - Paolo P. Lava (paoloplava(AT)gmail.com), Jun 04 2008
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CROSSREFS
| Sequence in context: A082828 A204299 A083962 * A079794 A197106 A138568
Adjacent sequences: A007939 A007940 A007941 * A007943 A007944 A007945
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KEYWORD
| nonn,base,easy
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AUTHOR
| R. Muller
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