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A109241 Expansion of 1/((1-10*x)*(1-100*x)). 8

%I #43 Sep 08 2022 08:45:19

%S 1,110,11100,1111000,111110000,11111100000,1111111000000,

%T 111111110000000,11111111100000000,1111111111000000000,

%U 111111111110000000000,11111111111100000000000,1111111111111000000000000,111111111111110000000000000,11111111111111100000000000000

%N Expansion of 1/((1-10*x)*(1-100*x)).

%C a(n) has n+1 1's and n 0's. Partial sums are A109242.

%C a(n) = A171476(n) converted from decimal to binary. - _Robert Price_, Jan 19 2016

%C Also the binary representation of the n-th iteration of the elementary cellular automaton starting with a single ON (black) cell for Rules 206 and 238. - _Robert Price_, Feb 21 2016

%D S. Wolfram, A New Kind of Science, Wolfram Media, 2002; p. 55.

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/ElementaryCellularAutomaton.html">Elementary Cellular Automaton</a>

%H S. Wolfram, <a href="http://wolframscience.com/">A New Kind of Science</a>

%H <a href="https://oeis.org/wiki/Index_to_Elementary_Cellular_Automata">Index to Elementary Cellular Automata</a>

%H <a href="/index/Ce#cell">Index entries for sequences related to cellular automata</a>

%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (110,-1000)

%F a(n) = (10^(2n+1) - 10^n)/9.

%F a(n) = A006516(n+1) written in base 2. - _Omar E. Pol_, Feb 24 2008

%F a(n) = A138147(n+1)/10. - _Omar E. Pol_, Nov 08 2008

%F a(n) = 110*a(n-1) -1000*a(n-2), n>=2. - _Vincenzo Librandi_, Mar 18 2011

%F a(n) = A002275(n+1)*10^n. - _Wesley Ivan Hurt_, Jun 22 2013

%F E.g.f.: (1/9)*(10*exp(100*x) - exp(10*x)). - _G. C. Greubel_, Aug 01 2017

%p A109241 := proc(n)(10^(2*n+1)-10^n)/9 ; end proc:

%p seq(A109241(n),n=0..20) ; # _R. J. Mathar_, Mar 21 2011

%t Table[(10^(2*n+1)-10^n)/9, {n, 0, 100}] (* _Robert Price_, Feb 21 2016 *)

%t CoefficientList[Series[1/((1 - 100 x) (1 - 10 x)), {x, 0, 33}], x] (* _Vincenzo Librandi_, Feb 22 2016 *)

%o (PARI) a(n)=10^(2*n+1)/9-10^n/9 \\ _Charles R Greathouse IV_, Oct 07 2015

%o (Magma) [10^(2*n+1)/9-10^n/9: n in [0..40]]; // _Vincenzo Librandi_, Feb 22 2016

%Y Cf. A006516, A138147.

%K easy,nonn

%O 0,2

%A _Paul Barry_, Jun 23 2005

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Last modified March 18 22:56 EDT 2024. Contains 370952 sequences. (Running on oeis4.)