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A122842
Square roots of the odd indexed terms of A038547.
4
1, 3, 9, 27, 15, 243, 729, 45, 6561, 19683, 135, 177147, 225, 105, 4782969, 14348907, 1215, 675, 387420489, 3645, 3486784401, 10460353203, 315, 94143178827, 3375, 32805, 2541865828329, 6075, 98415, 68630377364883
OFFSET
1,2
COMMENTS
A038547(n) is the least number with exactly n odd divisors. For odd n these are perfect squares.
LINKS
FORMULA
a(n) = sqrt(A038547(2*n-1)).
a(n) = sqrt(A119265(2*n-1, 2*n-1)).
a(n) = 3^(n-1) for n = (p+1)/2, where p is an odd prime.
a(3*n+2) = 5*3^n for n = (p-1)/2, where p is an odd prime.
EXAMPLE
a(1) = 1 because A038547(1) = 1.
a(2) = 3 because A038547(3) = 9.
a(5) = 15 because A038547(9) = 225.
MATHEMATICA
(* Function a038547[ ] is defined in A038547 *)
a122842[n_]:=Sqrt[a038547[2n-1]]
Map[a122842, Range[30]] (* Hartmut F. W. Hoft, Feb 07 2023 *)
KEYWORD
nonn
AUTHOR
Alexander Adamchuk, Sep 13 2006, Sep 25 2006
EXTENSIONS
More terms from R. J. Mathar, Sep 20 2006
Edited by Hartmut F. W. Hoft, Feb 07 2023
STATUS
approved