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A165925
Irregular triangle read by rows: square-full quadratic non-residues.
3
8, 8, 8, 8, 8, 12, 8, 12, 8, 12, 12, 8, 12, 8, 12, 18, 8, 12, 18, 8, 12, 20, 8, 18, 20, 8, 18, 20, 8, 12, 18, 20, 8, 18, 20, 24, 8, 12, 18, 20, 24, 12, 18, 20, 24, 27, 8, 12, 18, 27, 8, 12, 18, 20, 27, 28, 12, 24, 27, 8, 12, 18, 20, 24, 27, 28, 8, 18, 20, 24, 28, 32, 12, 20, 24, 27, 28
OFFSET
9,1
COMMENTS
The irregular triangle of numbers is:
..n....Square-full quadratic non-residues
..1....
..2....
..3....
..4....
..5....
..6....
..7....
..8....
..9.....8
.10.....8
.11.....8
.12.....8
.13.....8
.14....12
.15.....8.12
.16.....8.12
.17....12
.18.....8.12
.19.....8.12.18
.20.....8.12.18
.21.....8.12.20
.22.....8.18
.23....20
.24.....8.18.20
.25.....8.12.18.20
.26.....8.18.20.24
.27.....8.12.18.20.24
.28....12.18.20.24.27
.29.....8.12.18.27
.30.....8.12.18.20.27.28
.31....12.24.27
.32.....8.12.18.20.24.27.28
.33.....8.18.20.24.28.32
.34....12.20.24.27.28
MATHEMATICA
Flatten[Table[Select[Complement[Range[n - 1], Mod[Range[n/2]^2, n]], ! SquareFreeQ[#] &], {n, 9, 34}]] (* T. D. Noe, Nov 22 2011 *)
CROSSREFS
Cf. A096013.
Sequence in context: A245401 A048763 A088841 * A165926 A216865 A216412
KEYWORD
nonn,tabf
AUTHOR
STATUS
approved