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%I #17 Oct 04 2013 11:19:05
%S 1,9,63,1,522,144,487,6921,5202,5203,6534,4806,1828,52011,441,69481,
%T 90432,14292,163,144,16335,90046,67167,9,526501,102321,488241,638461,
%U 522981,522612,610642,487872,127413,520453,9693,655344,902494,180945,4806,4276,123147
%N Squares of triangular numbers, written backwards.
%H K. D. Bajpai, <a href="/A229701/b229701.txt">Table of n, a(n) for n = 1..1000</a>
%F n-th triangular number = T(n) = n*(n+1)/2.
%e a(3) = 63: T(3) = 3/2*(3+1) = 6 and 6^2 = 36. Writing it backwards gives 63.
%e a(6) = 144: T(6) = 6/2*(6+1) = 21 and 21^2 = 441. Writing it backwards gives 144.
%p with(StringTools):KD:= proc() local a; a:= parse(Reverse(convert(((n/2*(n+1))^2),string))); RETURN (a): end: seq(KD(),n=1..100);
%t Table[FromDigits[Reverse[IntegerDigits[(n*(n + 1)/2)^2]]], {n, 1, 100}]
%Y Cf. A004158.
%K nonn,base,less
%O 1,2
%A _K. D. Bajpai_, Sep 27 2013
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