A331827 Positive negabinary-Niven numbers k (A331728) such that -k is a negative negabinary-Niven number (A331819).

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

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 A364291 A316860

Adjacent sequences: A331824 A331825 A331826 * A331828 A331829 A331830

Keyword

nonn,base

Author

Amiram Eldar, Jan 28 2020

Status

approved