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A078257 a(n) = denominator(N) where N = 0.123...n (concatenation of 1 to n after decimal point). 4
10, 25, 1000, 5000, 20000, 15625, 10000000, 50000000, 1000000000, 10000000000, 10000000000000, 125000000000000, 100000000000000000, 5000000000000000000, 200000000000000000000, 25000000000000000000000, 10000000000000000000000000, 500000000000000000000000000, 100000000000000000000000000000 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Conjecture: sequence is not equal to the sequence of denominators presented in A172495 and A172506. [Jaroslav Krizek, Feb 05 2010]

LINKS

Table of n, a(n) for n=1..19.

EXAMPLE

a(1) = 10 as 10*0.1 = 1, a(2) = 25 as 25*0.12 = 3.

PROG

(PARI) a(n) = {my(s = ""); for (k=1, n, s = concat(s, Str(k))); denominator(eval(s)/10^(#s)); } \\ Michel Marcus, Jan 15 2019

CROSSREFS

Cf. A078258 (numerators).

Sequence in context: A219377 A156183 A124870 * A059198 A259297 A046961

Adjacent sequences:  A078254 A078255 A078256 * A078258 A078259 A078260

KEYWORD

base,nonn,frac

AUTHOR

Amarnath Murthy, Nov 24 2002

EXTENSIONS

More terms from Sascha Kurz, Jan 04 2003

More terms from Michel Marcus, Jan 15 2019

STATUS

approved

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Last modified August 14 18:13 EDT 2022. Contains 356122 sequences. (Running on oeis4.)