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A166715
Irregular triangle read by rows: row n lists nonzero quadratic residues modulo the n-th term of A123239.
2
1, 1, 1, 3, 4, 5, 9, 1, 3, 4, 9, 10, 12, 1, 3, 4, 7, 9, 10, 11, 12, 16, 21, 25, 26, 27, 28, 30, 33, 34, 36, 1, 2, 4, 5, 8, 9, 10, 16, 18, 20, 21, 23, 25, 31, 32, 33, 36, 37, 39, 40, 1, 3, 4, 5, 7, 9, 12, 15, 16, 17, 19, 20, 21, 22, 25, 26, 27
OFFSET
1,4
LINKS
Eric Weisstein's World of Mathematics, Quadratic Residue.
EXAMPLE
Triangle starts:
1;
1;
1,3,4,5,9;
1,3,4,9,10,12;
...
Modulo A123239(3)=11, the quadratic residues are 1,3,4,5,9.
MATHEMATICA
MangammalQ[p_]:=Block[{k=3}, While[k>2, k=Mod[3k, p]]; k!=2];
A123239=Select[Prime[Range[17]], MangammalQ];
A166715=Flatten[Union[Mod[Range[Floor[#/2]]^2, #]]&/@A123239] (* Ray Chandler, Jul 21 2011 *)
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
A.K. Devaraj, Oct 20 2009
EXTENSIONS
Edited by N. J. A. Sloane, Oct 22 2009
Edited by Charles R Greathouse IV, Oct 28 2009
Edited, corrected and extended by Ray Chandler, Jul 21 2011
STATUS
approved