A021017 - OEIS

A021017

Decimal expansion of 1/13.

0, 7, 6, 9, 2, 3, 0, 7, 6, 9, 2, 3, 0, 7, 6, 9, 2, 3, 0, 7, 6, 9, 2, 3, 0, 7, 6, 9, 2, 3, 0, 7, 6, 9, 2, 3, 0, 7, 6, 9, 2, 3, 0, 7, 6, 9, 2, 3, 0, 7, 6, 9, 2, 3, 0, 7, 6, 9, 2, 3, 0, 7, 6, 9, 2, 3, 0, 7, 6, 9, 2, 3, 0, 7, 6, 9, 2, 3, 0, 7, 6, 9, 2, 3, 0, 7, 6, 9, 2, 3, 0, 7, 6, 9, 2, 3, 0, 7, 6

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OFFSET

0,2

COMMENTS

In 1741, Euler recognized that 10 times this number is close to (2^i + 2^(-i))/2, see Nahin (1988) and A219705. - Alonso del Arte, Nov 25 2012

Also decimal expansion of sum(i=1..infinity, 1/14^i). [Bruno Berselli, Jan 03 2014]

REFERENCES

Paul J. Nahin, An Imaginary Tale: The Story of sqrt(-1). Princeton, New Jersey: Princeton University Press (1988): 143.

LINKS

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

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

FORMULA

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

EXAMPLE

0.076923076923076923076923076923076923076923...

MATHEMATICA

LinearRecurrence[{1, 0, -1, 1}, {0, 7, 6, 9}, 98] (* with C. Barker's formula, Peter Luschny, Aug 15 2012 *)

Join[{0}, RealDigits[1/13, 10, 120][[1]]] (* or *) PadRight[{}, 120, {0, 7, 6, 9, 2, 3}] (* Harvey P. Dale, Dec 17 2017 *)

CROSSREFS

Cf. A219705.

Sequence in context: A351687 A011220 A198605 * A219705 A273066 A257964

Adjacent sequences: A021014 A021015 A021016 * A021018 A021019 A021020

KEYWORD

nonn,cons,easy

AUTHOR

N. J. A. Sloane.

STATUS

approved