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 A110575 Numbers k that divide A110574(k); or k such that A110574(k) is a Niven number. 1

%I #14 Mar 01 2024 07:16:27

%S 1,3,7,9,13,23,171,399,819,8673,17263

%N Numbers k that divide A110574(k); or k such that A110574(k) is a Niven number.

%C a(12) > 138000, if it exists. - _Amiram Eldar_, Mar 01 2024

%e a(3) = 7 because 1101001100101/7 = 157285871443.

%t seq[max_] := Module[{o = Select[Range[2*max], OddQ[DigitCount[#, 2][[1]]] &], sum = 0, s = {}}, Do[sum += 10^(o[[k]] - 1); If[Divisible[IntegerReverse[sum], k], AppendTo[s, k]], {k, 1, Length[o]}]; s]; seq[1000] (* _Amiram Eldar_, Mar 01 2024 *)

%Y Cf. A005349, A110574.

%K nonn,base,more

%O 1,2

%A _Jason Earls_, Jul 28 2005

%E a(10)-a(11) from _Amiram Eldar_, Mar 01 2024

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Last modified September 12 15:01 EDT 2024. Contains 375852 sequences. (Running on oeis4.)