A269819 -id:A269819 - cp's OEIS frontend

A331087 Starts of runs of 3 consecutive positive negaFibonacci-Niven numbers (A331085).

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

Offset: 1

Amiram Eldar, Jan 08 2020

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.

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

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

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

A331090 Positive numbers k such that -k, -(k + 1), and -(k + 2) are 3 consecutive negative negaFibonacci-Niven numbers (A331088).

Original entry on oeis.org

1, 2, 20, 54, 55, 56, 110, 376, 398, 974, 986, 1084, 1744, 2464, 2524, 3304, 3870, 5223, 5718, 6095, 6124, 6184, 6663, 6764, 6844, 7142, 7684, 9035, 9124, 10590, 11598, 11975, 12606, 13444, 13504, 14284, 14915, 17164, 17643, 17710, 17714, 17824, 17884, 18698, 18905, 19494, 23191, 24243, 24785, 25542, 26382, 27390, 29644, 34278, 35464

Offset: 1

Amiram Eldar, Jan 08 2020

Numbers of the form F(6*k + 2) - 1 and F(6*k + 4) - 1, where F(m) is the m-th Fibonacci number, are terms.

If m is of the form F(k) - 1, where k > 2 is congruent to {2, 10} mod 24, then {-m, -(m + 1), -(m + 2), -(m + 3), -(m + 4)} are 5 consecutive negative negaFibonacci-Niven numbers.

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

Cf. A000045, A154701, A269819, A328210, A328214, A330932, A331087, A331088.

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

cp's OEIS Frontend

A331087 Starts of runs of 3 consecutive positive negaFibonacci-Niven numbers (A331085).

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