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A068094 Number of n-digit triangular numbers. 6

%I #7 Dec 05 2013 19:55:10

%S 3,10,31,96,306,967,3058,9670,30579,96700,305793,967000,3057922,

%T 9670000,30579224,96699996,305792239,966999967,3057922393,9669999669,

%U 30579223926,96699996687,305792239263,966999966873,3057922392627,9669999668731,30579223926265

%N Number of n-digit triangular numbers.

%F Differences of successive terms of A068092.

%t triInverse[n_] := Floor[(Sqrt[1 + 8*n] - 1)/2]; Differences[Table[triInverse[10^(n - 1) - 1], {n, 30}]] (* _T. D. Noe_, Jul 27 2012 *)

%Y Cf. A068092, A068093, A095863, A095864, A095865, A095866.

%K base,easy,nonn

%O 1,1

%A _Amarnath Murthy_, Feb 19 2002

%E More terms from _Sascha Kurz_, Mar 06 2002

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Last modified April 25 06:49 EDT 2024. Contains 371964 sequences. (Running on oeis4.)