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A165919
Irregular triangle read by rows: square-full nonzero quadratic residues mod n.
3
4, 4, 4, 4, 4, 4, 9, 4, 9, 4, 9, 4, 9, 12, 4, 8, 9, 4, 9, 4, 9, 4, 8, 9, 16, 4, 9, 16, 4, 9, 16, 4, 9, 16, 4, 9, 16, 18, 4, 9, 12, 16, 20, 4, 8, 9, 12, 16, 18, 4, 9, 12, 16, 4, 9, 16, 24, 4, 9, 12, 16, 25, 4, 9, 16, 25, 4, 8, 9, 16, 25, 4, 9, 16, 20, 24, 25, 28, 4, 9, 16, 24, 25
OFFSET
5,1
COMMENTS
The irregular triangle of numbers is:
..n....Square-full nonzero quadratic residues
..1....
..2....
..3....
..4....
..5.....4
..6.....4
..7.....4
..8.....4
..9.....4
.10.....4..9
.11.....4..9
.12.....4..9
.13.....4..9.12
.14.....4..8..9
.15.....4..9
.16.....4..9
.17.....4..8..9.16
.18.....4..9.16
.19.....4..9.16
.20.....4..9.16
.21.....4..9.16.18
.22.....4..9.12.16.20
.23.....4..8..9.12.16.18
.24.....4..9.12.16
.25.....4..9.16.24
.26.....4..9.12.16.25
.27.....4..9.16.25
.28.....4..8..9.16.25
.29.....4..9.16.20.24.25
.30.....4..9.16.24.25
CROSSREFS
Cf. A046071.
Sequence in context: A049109 A035651 A007208 * A035637 A001736 A247969
KEYWORD
nonn,tabf
AUTHOR
EXTENSIONS
Minor edit and cross-reference added by Christopher Hunt Gribble, Oct 05 2009
Offset set to 5, keyword:tabf added - R. J. Mathar, Oct 09 2009
STATUS
approved