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 A331827 Positive negabinary-Niven numbers k (A331728) such that -k is a negative negabinary-Niven number (A331819). 2
 2, 3, 4, 6, 8, 9, 12, 15, 16, 18, 20, 24, 28, 30, 32, 33, 36, 40, 42, 48, 54, 56, 60, 63, 64, 66, 68, 72, 78, 80, 84, 90, 96, 100, 102, 108, 112, 114, 120, 124, 126, 128, 129, 132, 136, 138, 140, 144, 150, 156, 160, 162, 168, 174, 175, 180, 186, 192, 198, 200 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Positive numbers k that are divisible by the sums of digits in the negabinary representations of both k and -k. All the powers of 2 above 1 are terms. LINKS Amiram Eldar, Table of n, a(n) for n = 1..10000 MATHEMATICA negaBinWt[n_] := negaBinWt[n] = If[n==0, 0, negaBinWt[Quotient[n-1, -2]] + Mod[n, 2]]; seqQ[n_] := And @@ (Divisible[n, negaBinWt[#]] & /@ {-n, n}); Select[Range[200], seqQ] CROSSREFS Intersection of A331728 and A331819. Cf. A330711, A331091. Sequence in context: A122380 A033501 A336504 * A231404 A316860 A097273 Adjacent sequences:  A331824 A331825 A331826 * A331828 A331829 A331830 KEYWORD nonn,base AUTHOR Amiram Eldar, Jan 28 2020 STATUS approved

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Last modified May 16 22:18 EDT 2021. Contains 343957 sequences. (Running on oeis4.)