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A331087 Starts of runs of 3 consecutive positive negaFibonacci-Niven numbers (A331085). 13
4, 12, 86, 87, 88, 176, 230, 231, 232, 320, 464, 655, 1194, 1592, 1596, 1854, 1914, 2815, 3016, 3294, 4124, 4178, 4179, 4180, 4268, 4412, 5663, 5755, 8360, 9894, 10614, 10703, 10915, 10975, 13936, 14994, 15114, 15714, 17630, 18976, 19984, 20824, 21835, 23175, 23513 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Numbers of the form F(6*k + 1) - 1, where F(m) is the m-th Fibonacci number, are terms.

Numbers of the form F(k) - 3, where k is congruent to {5, 11, 13, 19} mod 24 (A269819) are starts of runs of 5 consecutive negaFibonacci-Niven numbers.

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000

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];

negFibQ[n_] := Divisible[n, negaFibTermsNum[n]];

nConsec = 3; neg = negFibQ /@ Range[nConsec]; seq = {}; c = 0; k = nConsec + 1; While[c < 55, If[And @@ neg, c++; AppendTo[seq, k - nConsec]]; neg = Join[Rest[neg], {negFibQ[k]}]; k++]; seq

CROSSREFS

Cf. A000045, A154701, A269819, A328210, A328214, A330932, A331085.

Sequence in context: A208802 A226960 A081214 * A194004 A064280 A203379

Adjacent sequences:  A331084 A331085 A331086 * A331088 A331089 A331090

KEYWORD

nonn,base

AUTHOR

Amiram Eldar, Jan 08 2020

STATUS

approved

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Last modified August 10 20:05 EDT 2022. Contains 356039 sequences. (Running on oeis4.)