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 A263930 Number of quasi-Carmichael numbers less than 10^n. 0
 0, 2, 27, 165, 734, 3109, 11568, 40820, 137850, 457191 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS For quasi-Carmichael numbers see A257750. LINKS EXAMPLE a(1) = 0 because there are no quasi-Carmichael numbers below 10^1. a(2) = 2 because there are two quasi-Carmichael numbers below 10^2, namely, 35 and 77. PROG (Perl) use ntheory ":all"; my(\$s, \$e)=(0, 1); forcomposites { say \$e++, " \$s" if \$_ >= 10**\$e; \$s++ if is_quasi_carmichael(\$_) } 1e7; # Dana Jacobsen, Apr 27 2017 CROSSREFS Cf. A055553, A216929, A257750. Sequence in context: A166942 A119351 A098627 * A051766 A058406 A216087 Adjacent sequences:  A263927 A263928 A263929 * A263931 A263932 A263933 KEYWORD nonn,more,hard AUTHOR Tim Johannes Ohrtmann, Oct 30 2015 EXTENSIONS a(8)-a(10) from Dana Jacobsen, Apr 27 2017 STATUS approved

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Last modified February 26 19:13 EST 2020. Contains 332294 sequences. (Running on oeis4.)