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 A335708 a(n) is the number of divisors of the n-th Niven number. 1
 1, 2, 2, 3, 2, 4, 2, 4, 3, 4, 6, 6, 6, 4, 8, 4, 8, 9, 8, 8, 6, 10, 6, 8, 12, 6, 8, 12, 10, 5, 12, 12, 9, 8, 12, 8, 4, 10, 8, 6, 16, 12, 12, 4, 8, 12, 15, 12, 8, 6, 12, 10, 6, 18, 8, 14, 8, 12, 12, 4, 12, 6, 4, 16, 16, 12, 8, 12, 9, 12, 8, 12, 20, 6, 4, 18, 6, 16 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS FORMULA a(n) = A000005(A005349(n)). EXAMPLE The first Niven number is 1 and tau(1) = 1, so a(1) = 1. The second Niven number is 2 and tau(2) = 2, so a(2) = 2. The 11th Niven number is 12 and tau(12) = 6, so a(11) = 6. MATHEMATICA DivisorSigma[0, Select[Range[265], Divisible[#, Plus @@ IntegerDigits[#]] &]] (* Amiram Eldar, Aug 04 2020 *) PROG (MAGMA) niven:=func; [#Divisors(k):k in [1..300]|niven(k)]; CROSSREFS Cf. A000005, A005349, A007953. Sequence in context: A218704 A144373 A086292 * A076640 A326198 A324105 Adjacent sequences:  A335705 A335706 A335707 * A335709 A335710 A335711 KEYWORD nonn,base AUTHOR Marius A. Burtea, Aug 04 2020 STATUS approved

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Last modified August 4 09:11 EDT 2021. Contains 346445 sequences. (Running on oeis4.)