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A172506 a(n) = numerator of fraction a/b, where gcd(a, b) = 1, whose decimal representation has the form (1)(2)(3)...(n-1)(n).(1)(2)(3)...(n-1)(n). 1
11, 303, 123123, 6170617, 246902469, 1929001929, 12345671234567, 617283906172839 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Sequence of denominators: 10, 25, 1000, 5000, 20000, 15625, 10000000, 50000000, ... Conjecture: this sequence is not equal to the sequence A078257.

LINKS

Table of n, a(n) for n=1..8.

EXAMPLE

a(6) = 1929001929; 1929001929/15625 = 123456.123456.

CROSSREFS

Sequence in context: A012192 A012079 A180056 * A250551 A001280 A100445

Adjacent sequences:  A172503 A172504 A172505 * A172507 A172508 A172509

KEYWORD

nonn

AUTHOR

Jaroslav Krizek, Feb 05 2010

STATUS

approved

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Last modified October 19 14:00 EDT 2021. Contains 348090 sequences. (Running on oeis4.)