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 A034056 Numbers with multiplicative digital root value 9. 13
 9, 19, 33, 91, 119, 133, 191, 313, 331, 911, 1119, 1133, 1191, 1313, 1331, 1911, 3113, 3131, 3311, 9111, 11119, 11133, 11191, 11313, 11331, 11911, 13113, 13131, 13311, 19111, 31113, 31131, 31311, 33111, 91111, 111119, 111133, 111191, 111313, 111331 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Numbers with one 9 or two 3s, and zero or more 1s. - Daniel Forgues, Oct 09 2011 LINKS Eric Weisstein's World of Mathematics, Multiplicative Digital Root FORMULA There are n(n+1)(n+2)/6 elements up to 10^n, so a(n) is about 10^sqrt(6n). CROSSREFS Cf. A031347. Cf. A034048, A002275, A034049, A034050, A034051, A034052, A034053, A034054, A034055, A034056 (numbers having multiplicative digital roots 0-9). Sequence in context: A250663 A274590 A051811 * A195042 A198590 A297396 Adjacent sequences:  A034053 A034054 A034055 * A034057 A034058 A034059 KEYWORD nonn,base,easy AUTHOR Patrick De Geest, Sep 15 1998 STATUS approved

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Last modified April 18 10:21 EDT 2021. Contains 343087 sequences. (Running on oeis4.)