login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A021023 Decimal expansion of 1/19. 5
0, 5, 2, 6, 3, 1, 5, 7, 8, 9, 4, 7, 3, 6, 8, 4, 2, 1, 0, 5, 2, 6, 3, 1, 5, 7, 8, 9, 4, 7, 3, 6, 8, 4, 2, 1, 0, 5, 2, 6, 3, 1, 5, 7, 8, 9, 4, 7, 3, 6, 8, 4, 2, 1, 0, 5, 2, 6, 3, 1, 5, 7, 8, 9, 4, 7, 3, 6, 8, 4, 2, 1, 0, 5, 2, 6, 3, 1, 5, 7, 8, 9, 4, 7, 3, 6, 8, 4, 2, 1, 0, 5, 2, 6, 3, 1, 5, 7, 8 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

The 18-digit cycle 1,0,5,2,6,3,1,5,7,8,9,4,7,3,6,8,4,2 in this sequence and the others based on nineteenths gives the successive digits of the smallest integer which is doubled, quadrupled and octupled when the last three digits in turn are moved from the right hand end to the left hand end. For example, 842105263157894736 is eight times 105263157894736842. [From Ian Duff, Jan 07 2009, Jan 12 2009]~

The magic square that uses the decimals of 1/19 is fully magic. 383 has the same property (see A021387). For other such primes see A072359. - Michel Marcus, Sep 02 2015

REFERENCES

Martin Gardner, Cyclic numbers, Mathematical Circus, Chapter 10, p. 172, of the 1992 Mathematical Association of America edition.

LINKS

Table of n, a(n) for n=0..98.

Wikipedia, Prime reciprocal magic square

Index entries for linear recurrences with constant coefficients, signature (1,0,0,0,0,0,0,0,-1,1).

FORMULA

G.f.: -x*(x^8+x^7+2*x^6+4*x^5-2*x^4-3*x^3+4*x^2-3*x+5)/((x-1)*(x+1)*(x^2-x+1)*(x^6-x^3+1)). [Colin Barker, Aug 15 2012]

MATHEMATICA

Prepend[First@ RealDigits[N[1/19, 120]], 0] (* Michael De Vlieger, Sep 02 2015 *)

PROG

(PARI) default(realprecision, 2000); 1/19.0 \\ Anders Hellström, Sep 02 2015

CROSSREFS

Cf. A021387, A072359.

Sequence in context: A018247 A152025 A021099 * A078716 A164103 A054863

Adjacent sequences:  A021020 A021021 A021022 * A021024 A021025 A021026

KEYWORD

nonn,cons,easy

AUTHOR

N. J. A. Sloane.

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified January 22 23:00 EST 2019. Contains 319365 sequences. (Running on oeis4.)