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%I #6 Oct 31 2013 12:17:38
%S 1,3,15,21,105,171,231,741,903,1275,1485,1711,2211,2415,3003,3403,
%T 3655,4095,4465,4851,5151,5253,5671,7503,8001,8515,10153,10585,10731,
%U 11781,13203,13695,13861,17391,18145,18915,19503,21115,22155,22791,24531
%N Numbers which are both lucky and triangular.
%H Donovan Johnson, <a href="/A118565/b118565.txt">Table of n, a(n) for n = 1..3537</a>
%t triQ[n_] := IntegerQ@Sqrt[8n+1]; lst = Range[1, 26564, 2]; i = 2; While[ i <= (len = Length@lst) && (k = lst[[i]]) <= len, lst = Drop[lst, {k, len, k}]; i++ ]; Select[lst, triQ@# &] (* _Robert G. Wilson v_ *)
%Y Cf. A000959, A000217.
%K nonn
%O 1,2
%A Luc Stevens (lms022(AT)yahoo.com), May 07 2006
%E Corrected and extended by Adam Panagos (adam.panagos(AT)gmail.com) and _Robert G. Wilson v_, May 10 2006
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