A165919 - OEIS

%I #6 May 01 2013 21:13:44

%S 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,

%T 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,

%U 12,16,25,4,9,16,25,4,8,9,16,25,4,9,16,20,24,25,28,4,9,16,24,25

%N Irregular triangle read by rows: square-full nonzero quadratic residues mod n.

%C The irregular triangle of numbers is:

%C ..n....Square-full nonzero quadratic residues

%C ..1....

%C ..2....

%C ..3....

%C ..4....

%C ..5.....4

%C ..6.....4

%C ..7.....4

%C ..8.....4

%C ..9.....4

%C .10.....4..9

%C .11.....4..9

%C .12.....4..9

%C .13.....4..9.12

%C .14.....4..8..9

%C .15.....4..9

%C .16.....4..9

%C .17.....4..8..9.16

%C .18.....4..9.16

%C .19.....4..9.16

%C .20.....4..9.16

%C .21.....4..9.16.18

%C .22.....4..9.12.16.20

%C .23.....4..8..9.12.16.18

%C .24.....4..9.12.16

%C .25.....4..9.16.24

%C .26.....4..9.12.16.25

%C .27.....4..9.16.25

%C .28.....4..8..9.16.25

%C .29.....4..9.16.20.24.25

%C .30.....4..9.16.24.25

%H C. H. Gribble, <a href="/A165919/b165919.txt">Flattened irregular triangle read by rows as table of j, a(j) for j = 5..69744 (rows 5:1000)</a>. [Entries in b-file edited by _N. J. A. Sloane_, Oct 04 2010]

%Y Cf. A046071.

%K nonn,tabf

%O 5,1

%A _Christopher Hunt Gribble_, Sep 30 2009

%E Minor edit and cross-reference added by _Christopher Hunt Gribble_, Oct 05 2009

%E Offset set to 5, keyword:tabf added - _R. J. Mathar_, Oct 09 2009