A176913 Numbers k with maximal exponent in prime factorization equal to 1, such that k+1 has maximal exponent 2, k+2 has maximal exponent 3, and k+3 has maximal exponent 4.

2022, 11149, 11373, 17574, 22381, 25037, 26701, 27949, 31210, 36123, 49974, 61395, 65581, 67373, 70541, 75373, 75949, 88747, 97549, 103373, 108294, 110886, 112045, 114774, 118285, 147174, 159757, 162349, 172717, 174390, 175373, 195531, 202957

Offset

1,1

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Example

a(1) = 2022 from 2022 = 2*3*337, 2023 = 7*17^2, 2024 = 2^3*11*23, and 2025 = 3^4*5^2.

Mathematica

f[n_]:=Max[Last/@FactorInteger[n]]; lst={}; Do[If[f[n]==1&&f[n+1]==2&&f[n+2]==3&&f[n+3]==4, AppendTo[lst, n]], {n, 2, 9!}]; lst
SequencePosition[Table[Max[FactorInteger[n][[;; , 2]]], {n, 250000}], {1, 2, 3, 4}][[;; , 1]] (* Harvey P. Dale, Aug 21 2024 *)

Crossrefs

Cf. A051903.

Sequence in context: A252327 A252326 A119423 * A013687 A257766 A359839

Adjacent sequences: A176910 A176911 A176912 * A176914 A176915 A176916

Keyword

nonn

Author

Vladimir Joseph Stephan Orlovsky, Apr 28 2010

Extensions

Edited by N. J. A. Sloane, Dec 29 2021

Status

approved