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A172496 a(n) = numerator of fraction a/b, where gcd(a, b) = 1, whose decimal representation has the form 0.(1)(2)(3)...(n-1)(n)... with period (1)(2)(3)...(n-1)(n). 2
1, 4, 41, 1234, 4115, 41152, 1234567, 1371742, 13717421, 12345678910, 411522630337, 41152263033704, 12345678910111213, 411522630337040438, 41152263033704043805, 12345678910111213141516, 137174210112346812683513, 13717421011234681268351302 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Denominators in A172498.
LINKS
EXAMPLE
a(10) = 12345678910; 12345678910/99999999999 = 0.1234567891012345678910... (period 12345678910).
MAPLE
a:= n-> (m-> numer(m*sum(10^(-i*length(m)), i=1..infinity))
)(parse(cat(seq(i, i=1..n)))):
seq(a(n), n=1..19); # Alois P. Heinz, Mar 31 2022
CROSSREFS
Sequence in context: A327026 A244751 A022515 * A059730 A006825 A333731
KEYWORD
nonn,base
AUTHOR
Jaroslav Krizek, Feb 05 2010
EXTENSIONS
More terms from Alois P. Heinz, Mar 31 2022
STATUS
approved

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Last modified June 18 07:40 EDT 2024. Contains 373469 sequences. (Running on oeis4.)