OFFSET
1,4
MATHEMATICA
a[n_]:=Det[Table[EulerPhi[i+j-1], {i, n}, {j, n}]]; Join[Array[a, 23]] (* Stefano Spezia, Feb 21 2025 *)
CROSSREFS
KEYWORD
sign
AUTHOR
N. J. A. Sloane, Aug 06 2000
EXTENSIONS
a(21)-a(23) from Stefano Spezia, Feb 21 2025
STATUS
approved