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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.
1
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
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
KEYWORD
nonn
AUTHOR
EXTENSIONS
Edited by N. J. A. Sloane, Dec 29 2021
STATUS
approved