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 A083910 Number of divisors of n that are congruent to 0 modulo 10. 12
 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 0 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,20 LINKS Reinhard Zumkeller, Table of n, a(n) for n = 1..10000 FORMULA a(n) = A000005(n) - A083911(n) - A083912(n) - A083913(n) - A083914(n) - A083915(n) - A083916(n) - A083917(n) - A083918(n) - A083919(n). a(10k) = tau(k) = A000005(k); a(n) = 0 if 10 does not divide n. - Franklin T. Adams-Watters, Apr 15 2007 G.f.: Sum_{k>=1} x^(10*k)/(1 - x^(10*k)). - Ilya Gutkovskiy, Sep 11 2019 MATHEMATICA ndc10[n_]:=Count[Divisors[n], _?(Divisible[#, 10]&)]; Array[ndc10, 110] (* Harvey P. Dale, Jan 05 2013 *) PROG (Haskell) a083910 = sum . map (a000007 . a010879) . a027750_row -- Reinhard Zumkeller, Jan 15 2013 (PARI) a(n)=if(n%10, 0, numdiv(n/10)) \\ Charles R Greathouse IV, Sep 27 2015 CROSSREFS Cf. A010879, A000005, A001227, A183063, A000007, A027750. Sequence in context: A173667 A241541 A086008 * A069843 A069849 A138045 Adjacent sequences:  A083907 A083908 A083909 * A083911 A083912 A083913 KEYWORD nonn AUTHOR Reinhard Zumkeller, May 08 2003 STATUS approved

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Last modified August 1 01:56 EDT 2021. Contains 346377 sequences. (Running on oeis4.)