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A020793
Decimal expansion of 1/6.
10
1, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6
OFFSET
0,2
COMMENTS
Except for the first term identical to A010722, A040006 and A021019. Except for the first terms the same as A021028, A021100, A021388, A071279, A101272, A168608, A177057,... - M. F. Hasler, Oct 24 2011
Decimal expansion of gamma(1) = 5/3 (with offset 1), where gamma(n) = Cp(n)/Cv(n) = is the n-th Poisson's constant. For the definition of Cp and Cv see A272002. - Natan Arie Consigli, Jul 10 2016
REFERENCES
Calvin C. Clawson, Mathematical Mysteries, The Beauty and Magic of Numbers, Springer, 2013, see p. 224.
FORMULA
a(n) = 6^n mod 10. - Zerinvary Lajos, Nov 26 2009
Equals Sum_{k>=1} 1/7^k. - Bruno Berselli, Jan 03 2014
10 * 1/6 = 5/3 = (5/2 R)/(3/2 R) = Cp(1)/Cv(1) = A272002/A272001, with R = A081822 (or A070064). - Natan Arie Consigli, Jul 10 2016
G.f.: (1 + 5*x)/(1 - x). - Ilya Gutkovskiy, Jul 10 2016
Equals Sum_{k>=1} 1/(k*Pi)^2. - Maciej Kaniewski, Sep 14 2017
Equals Sum_{k>=1} (zeta(2*k)-1)/4^k. - Amiram Eldar, Jun 08 2021
K_{n>=2} 2*n/(2*n - 3) = 5/3. (see Clawson at p. 224). - Stefano Spezia, Jul 01 2024
E.g.f.: 6*exp(x) - 5. - Elmo R. Oliveira, Aug 05 2024
MATHEMATICA
RealDigits[1/6, 10, 120][[1]] (* or *) PadRight[{1}, 120, {6}] (* Harvey P. Dale, Dec 30 2018 *)
PROG
(PARI) a(n)=6-5*!n \\ M. F. Hasler, Oct 24 2011
KEYWORD
nonn,cons,easy
STATUS
approved