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A165913
Irregular triangle read by rows: Squarefree nonzero quadratic residues.
3
1, 1, 1, 1, 1, 3, 1, 2, 1, 1, 7, 1, 5, 6, 1, 3, 5, 1, 1, 3, 10, 1, 2, 7, 11, 1, 6, 10, 1, 1, 2, 13, 15, 1, 7, 10, 13, 1, 5, 6, 7, 11, 17, 1, 5, 1, 7, 15, 1, 3, 5, 11, 14, 15, 1, 2, 3, 6, 13, 1, 1, 6, 11, 14, 19, 21, 1, 3, 10, 13, 14, 17, 22, 23, 1, 7, 10, 13, 19, 22, 1, 21, 1, 5, 6, 7, 13, 22, 23
OFFSET
1,6
COMMENTS
The irregular triangle of numbers is:
..n....Squarefree nonzero quadratic residues
..1....
..2....1
..3....1
..4....1
..5....1
..6....1..3
..7....1..2
..8....1
..9....1..7
.10....1..5..6
.11....1..3..5
.12....1
.13....1..3.10
.14....1..2..7.11
.15....1..6.10
.16....1
.17....1..2.13.15
.18....1..7.10.13
.19....1..5..6..7.11.17
.20....1..5
.21....1..7.15
.22....1..3..5.11.14.15
.23....1..2..3..6.13
.24....1
.25....1..6.11.14.19.21
.26....1..3.10.13.14.17.22.23
.27....1..7.10.13.19.22
.28....1.21
.29....1..5..6..7.13.22.23
CROSSREFS
Cf. A046071.
Sequence in context: A139436 A212305 A205555 * A256253 A288818 A319658
KEYWORD
nonn,tabf
AUTHOR
EXTENSIONS
Minor edit by Christopher Hunt Gribble, Oct 05 2009
STATUS
approved