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A175557 Prime preperiodic part of the decimal expansion of 1/k as k runs through A065502. 1
5, 2, 5, 41, 3, 2, 2, 2, 17, 13, 11, 89, 7, 5, 5, 5, 41, 3, 3, 347, 3, 3, 3, 29, 2, 2, 2, 2, 26041, 2, 2, 2, 23, 2, 2, 2, 2, 2, 17, 13, 13, 1201, 11, 11, 107, 919, 89, 7, 7, 7, 7, 7, 7, 61, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 41, 4111, 3 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Primes in A175555 in the order of appearance.

Multiples of 2 or 5 generate a quotient with a preperiodic sequence of digits, for example 1/24 = 0.041666666..., and 41 is the decimal form of the preperiodic part.

The corresponding values of n are: 2, 5, 20, 24, 28, 36, 44, 50, 56, 72, 88, 112, 136, 168, 184, ...

REFERENCES

H. Rademacher and O. Toeplitz, Von Zahlen und Figuren (Springer 1930, reprinted 1968), ch. 19, 'Die periodischen Dezimalbrueche'.

LINKS

Table of n, a(n) for n=1..69.

EXAMPLE

The prime 347 is in the sequence because 1/288 = .00347222222222222222...

The prime 1201 is in the sequence because 1/832 =.001201 923076 923076 ...

MAPLE

for n from 1 do

    p := A175555(n) ;

    if isprime(p) then

        print(p) ;

    end if;

end do: # R. J. Mathar, Jul 22 2012

CROSSREFS

Cf. A175555, A036275, A065502.

Sequence in context: A248260 A253382 A253384 * A217702 A018247 A152025

Adjacent sequences:  A175554 A175555 A175556 * A175558 A175559 A175560

KEYWORD

nonn,base

AUTHOR

Michel Lagneau, Jun 30 2010

STATUS

approved

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Last modified June 18 17:05 EDT 2019. Contains 324214 sequences. (Running on oeis4.)