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 A331086 Positive numbers k such that k and k + 1 are both negaFibonacci-Niven numbers (A331085). 7
 1, 4, 5, 9, 12, 13, 26, 68, 86, 87, 88, 89, 93, 99, 155, 176, 177, 183, 195, 212, 230, 231, 232, 233, 237, 243, 255, 320, 321, 327, 384, 395, 411, 415, 424, 464, 465, 471, 475, 484, 515, 544, 575, 591, 602, 644, 655, 656, 744, 824, 875, 894, 924, 1043, 1115, 1127 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Fibonacci numbers F(6*k - 1) and F(6*k) are terms. 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 = 2; 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. A328209, A328213, A330927, A330931, A331085. Sequence in context: A047610 A126004 A258251 * A332020 A184801 A228914 Adjacent sequences:  A331083 A331084 A331085 * A331087 A331088 A331089 KEYWORD nonn,base AUTHOR Amiram Eldar, Jan 08 2020 STATUS approved

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Last modified July 28 17:15 EDT 2021. Contains 346335 sequences. (Running on oeis4.)