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%I #3 Mar 30 2012 18:40:03
%S 96,225,1408,3400,9633,22016,43681,53600,93633,130625,152776,205408,
%T 308481,446216,696008,1493896,1628033,3280256,4617761,4928008,5595136,
%U 6720033,8473921,11721633,19995008,20919361,22863841,30752008,33340000
%N Octagonal numbers equal to S*(3S - 2) with 3S - 2 = k^2 and S semiprime.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/OctagonalNumber.html">Octagonal Number.</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/Semiprime.html">Semiprime.</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/16-Cell.html">16-Cell</a>
%F a(n) = A112392(n)*A112393(n).
%Y Cf. A112392, A112393.
%K easy,nonn
%O 1,1
%A _Giovanni Teofilatto_, Dec 13 2006, Dec 14 2006