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%I #14 Feb 24 2023 11:24:51
%S 1,3,15,36,66,105,171,253,378,496,666,861,1081,1378,1711,2080,2485,
%T 2926,3403,4005,4656,5356,6105,6903,7875,8778,9870,11026,12246,13530,
%U 14878,16471,17955,19701,21528,23436,25425,27495,29646,31878,34453,37128,39621,42486,45451,48516,52003,55278,58996,62481,66430,70125,74305,78606,83028,87990,92665,97461,102831
%N a(n) = m*(m+1)/2, where m = floor(n^(3/2)).
%C A subsequence of A000217, the triangular numbers.
%H Vincenzo Librandi, <a href="/A185541/b185541.txt">Table of n, a(n) for n = 1..10000</a>
%F a(n) = (1/2)*floor(n^3/2)*floor(1 + n^3/2).
%t f[n_]=Floor[n^(3/2)]*Floor[n^(3/2)+1]/2
%t Table[f[n],{n,1,80}]
%t (#(#+1))/2&/@Floor[Sqrt[Range[80]^3]] (* _Harvey P. Dale_, Feb 24 2023 *)
%o (Magma) [Floor(n^(3/2))*Floor(n^(3/2)+1)/2 : n in [1..60]]; // _Vincenzo Librandi_, Sep 13 2011
%Y Cf. A000217.
%K nonn
%O 1,2
%A _Clark Kimberling_, Jan 30 2011
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