OFFSET
1,1
COMMENTS
Every number in this sequence has the form 2^(2*i + 1) * k^(2*j), i,j>=0, k>=1.
The number of 1's in row a(n) of the triangle in A237048 as well as the length of that row are odd.
EXAMPLE
a(4) = 32 has 4 as its single middle divisor, and its symmetric representation of sigma consists of one part of width 1.
a(9) = 288 = 2^5 * 3^2 has 3 middle divisors - 12 = 2^2 * 3 , 16 = 2^4, 18 = 2 * 3^2 - and its symmetric representation of sigma consists of one part, the section of maximum width 3 of the single part includes the diagonal (see also A250068).
MATHEMATICA
(* Function a237271[ ] is defined in A237271 *)
a361903[n_] := Select[Range[n], IntegerQ[#/Sqrt[#/2]]&&a237271[#]==1&]
a361903[15000]
CROSSREFS
KEYWORD
nonn
AUTHOR
Hartmut F. W. Hoft, Mar 28 2023
STATUS
approved