A068783 Lesser of two consecutive numbers each divisible by a fifth power.

1215, 6560, 8991, 9375, 14336, 16767, 22112, 24543, 29888, 32319, 37664, 40095, 45440, 47871, 53216, 55647, 60992, 63423, 68768, 71199, 76544, 78975, 84320, 86751, 90624, 92096, 94527, 99872, 102303, 107648, 109375, 110079, 115424

Offset

1,1

Comments

The asymptotic density of this sequence is 1 - 2/zeta(5) + Product_{p prime} (1 - 2/p^5) = 0.000284512101137896862... - Amiram Eldar, Feb 16 2021

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000 (terms 1..1000 from Harvey P. Dale)

Mathematica

Select[ Range[2, 250000], Max[ Transpose[ FactorInteger[ # ]] [[2]]] > 4 && Max[ Transpose[ FactorInteger[ # + 1]] [[2]]] > 4 &]
SequencePosition[Table[If[Max[FactorInteger[n][[All, 2]]]>4, 1, 0], {n, 120000}], {1, 1}][[All, 1]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Dec 25 2018 *)

Crossrefs

Cf. A068780, A068781, A068140, A068782, A068784, A068785.

Sequence in context: A251815 A130680 A346207 * A331625 A235889 A321062

Adjacent sequences: A068780 A068781 A068782 * A068784 A068785 A068786

Keyword

nonn

Author

Robert G. Wilson v, Mar 04 2002

Status

approved