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A184337 a(n) is the integer whose decimal representation consists of n 8's followed by n 1's.

%I A184337 #52 Jul 03 2023 13:58:30
%S A184337 0,81,8811,888111,88881111,8888811111,888888111111,88888881111111,
%T A184337 8888888811111111,888888888111111111,88888888881111111111,
%U A184337 8888888888811111111111,888888888888111111111111,88888888888881111111111111
%N A184337 a(n) is the integer whose decimal representation consists of n 8's followed by n 1's.
%H A184337 Vincenzo Librandi, <a href="/A184337/b184337.txt">Table of n, a(n) for n = 0..200</a>
%H A184337 Richard Blecksmith and Charles Nicol, <a href="http://www.jstor.org/stable/2690745">Monotonic Numbers</a>, Mathematics Magazine, 66, (1993), 257-262.
%H A184337 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (111,-1110,1000).
%F A184337 a(n) = (8*100^n - 7*10^n - 1)/9.
%F A184337 a(n) = A059482(n)*A002283(n).
%F A184337 G.f.: 9*x*(-9+20*x) / ( (x-1)*(100*x-1)*(10*x-1) ). - _R. J. Mathar_, Feb 28 2011
%t A184337 Table[(8*100^n - 7*10^n - 1)/9, {n,0,30}] (* _G. C. Greubel_, Nov 02 2018 *)
%t A184337 FromDigits/@Table[Join[PadRight[{},n,8],PadRight[{},n,1]],{n,0,15}] (* or *) LinearRecurrence[ {111,-1110,1000},{0,81,8811},15] (* _Harvey P. Dale_, Jul 03 2023 *)
%o A184337 (Magma) [(8*100^n-7*10^n-1)/9: n in [0..20]]; // _Vincenzo Librandi_, Aug 04 2011
%o A184337 (PARI) vector(30, n, n--; (8*100^n - 7*10^n - 1)/9) \\ _G. C. Greubel_, Nov 02 2018
%o A184337 (Python)
%o A184337 for n in range(30):
%o A184337     print((8*100**n-7*10**n-1)//9, end=', ')
%o A184337 # _Stefano Spezia_, Nov 02 2018
%Y A184337 Cf. A098210 (with 1 and 5 instead of 8 and 1).
%Y A184337 Cf. A002283, A059482.
%Y A184337 Cf. A008591 (digits sums).
%K A184337 nonn,easy,base
%O A184337 0,2
%A A184337 _Paul Curtz_, Feb 13 2011