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A331091
Positive negaFibonacci-Niven numbers k (A331085) such that -k is a negative negaFibonacci-Niven number (A331088).
3
1, 2, 4, 6, 12, 18, 24, 27, 30, 36, 48, 55, 60, 72, 84, 90, 96, 100, 108, 110, 112, 116, 120, 144, 150, 156, 172, 176, 180, 184, 192, 196, 208, 228, 234, 240, 246, 252, 260, 264, 288, 300, 305, 320, 328, 330, 336, 340, 360, 372, 378, 384, 396, 400, 415, 420, 460, 468, 475, 480, 492
OFFSET
1,2
COMMENTS
Positive numbers k that are divisible by the number of terms in the negaFibonacci representations of both k and -k (A215022 and A215023, respectively).
LINKS
MATHEMATICA
ind[n_] := Floor[Log[Abs[n]*Sqrt[5] + 1/2]/Log[GoldenRatio]];
f[1] = 1; f[n_] := If[n > 0, i = ind[n - 1]; If[EvenQ[i], i++]; i, i = ind[-n]; If[OddQ[i], i++]; i];
negaFibTermsNum[n_] := Module[{k = n, s = 0}, While[k != 0, i = f[k]; s += 1; k -= Fibonacci[-i]]; s];
Select[Range[500], Divisible[#, negaFibTermsNum[#]] && Divisible[#, negaFibTermsNum[-#]] &]
CROSSREFS
Intersection of A331085 and A331088.
Sequence in context: A296505 A325283 A167706 * A072121 A349179 A175305
KEYWORD
nonn,base
AUTHOR
Amiram Eldar, Jan 08 2020
STATUS
approved