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A093851 a(n) = A002283(n-1) + floor(A052268(n)/(1+n)).

%I A093851 #20 Sep 08 2022 08:45:13
%S A093851 4,39,324,2799,24999,228570,2124999,19999999,189999999,1818181817,
%T A093851 17499999999,169230769229,1642857142856,15999999999999,
%U A093851 156249999999999,1529411764705881,14999999999999999,147368421052631577,1449999999999999999,14285714285714285713
%N A093851 a(n) = A002283(n-1) + floor(A052268(n)/(1+n)).
%C A093851 The first column r=1 of a triangle defined by T(n,r) = 10^(n-1) -1 + r*floor(9*10^(n-1)/(n+1)).
%C A093851 A row starts with a (virtual) 0th column of a rep-9-digit and fills the remainder with n+1 numbers in arithmetic progression with the largest step such that all numbers in the n-th row are n-digit numbers.
%H A093851 G. C. Greubel, <a href="/A093851/b093851.txt">Table of n, a(n) for n = 1..995</a>
%F A093851 a(n) = 10^(n-1) -1 + floor(9*10^(n-1)/(n+1)). - _G. C. Greubel_, Apr 02 2019
%e A093851 The triangle starts in row n=1 as
%e A093851 4 9 # -1, -1+5, -1+2*5
%e A093851 39 69 99 # 9,9+30,9+2*30
%e A093851 324 549 774 999 # 99, 99+225, 99+2*225, 99+3*225
%e A093851 2799 4599 6399 8199 9999 # 999, 999+1800, 999+2*1800,..
%e A093851 ...
%e A093851 The sequence contains the first column.
%p A093851 A093851 := proc(n) 10^(n-1)-1+floor(9*10^(n-1)/(n+1)) ; end proc: seq(A093851(n),n=1..20) ; # _R. J. Mathar_, Oct 14 2010
%t A093851 Table[10^(n-1) -1 +Floor[9*10^(n-1)/(n+1)], {n, 1, 20}] (* _G. C. Greubel_, Apr 02 2019 *)
%o A093851 (PARI) {a(n) = 10^(n-1) -1 +floor(9*10^(n-1)/(n+1))}; \\ _G. C. Greubel_, Apr 02 2019
%o A093851 (Magma) [10^(n-1) -1 +Floor(9*10^(n-1)/(n+1)): n in [1..20]]; // _G. C. Greubel_, Apr 02 2019
%o A093851 (Sage) [10^(n-1) -1 +floor(9*10^(n-1)/(n+1)) for n in (1..20)] # _G. C. Greubel_, Apr 02 2019
%Y A093851 Cf. A061772, A093846, A093847, A093450, A093552.
%K A093851 base,easy,nonn
%O A093851 1,1
%A A093851 _Amarnath Murthy_, Apr 18 2004
%E A093851 More terms from _R. J. Mathar_, Oct 14 2010