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 A068094 Number of n-digit triangular numbers. 6
 3, 10, 31, 96, 306, 967, 3058, 9670, 30579, 96700, 305793, 967000, 3057922, 9670000, 30579224, 96699996, 305792239, 966999967, 3057922393, 9669999669, 30579223926, 96699996687, 305792239263, 966999966873, 3057922392627, 9669999668731, 30579223926265 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS FORMULA Differences of successive terms of A068092. MATHEMATICA triInverse[n_] := Floor[(Sqrt[1 + 8*n] - 1)/2]; Differences[Table[triInverse[10^(n - 1) - 1], {n, 30}]] (* T. D. Noe, Jul 27 2012 *) CROSSREFS Cf. A068092, A068093, A095863, A095864, A095865, A095866. Sequence in context: A106517 A055217 A097472 * A100058 A002160 A214839 Adjacent sequences:  A068091 A068092 A068093 * A068095 A068096 A068097 KEYWORD base,easy,nonn AUTHOR Amarnath Murthy, Feb 19 2002 EXTENSIONS More terms from Sascha Kurz, Mar 06 2002 STATUS approved

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