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%I #5 Jan 19 2019 04:15:43
%S 18,21,49,130,1383,2660,3245,5730,9569,10735,11018,12054,13528,18249,
%T 19222,21483,22029,31665,31899,37804,40576,59322,59353,59966,65020,
%U 65972,73843,80938,82716,84445,85365,89866,92586,103639,105158,107149
%N 30*a(n) is the gap between sexy prime triples in the n-th sexy prime triple triple whose initial term is 17.
%C The nine terms in any sexy prime triple triple {{a, b, c}, {d, e, f}, {g, h, i}} may be arranged to form a 3 X 3 magic square [ h a f / c e g / d i b ].
%e a(2)=21 identifies the second sexy prime triple triple whose initial term is 17: {{17, 23, 29}, {17+30*21, 23+30*21, 29+30*21}, {17+2*30*21, 23+2*30*21, 29+2*30*21}} which is equal to {{17, 23, 29}, {647, 653, 659}, {1277, 1283, 1289}}.
%Y Cf. A023201, A046117.
%K nonn
%O 1,1
%A _Ray G. Opao_, Feb 16 2004