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a(n) = floor( Sum_{1 <= i < j <= n} ((sqrt(j)-sqrt(i))^3) ).
1

%I #7 Aug 16 2019 21:25:23

%S 0,0,1,4,8,16,27,43,64,92,128,172,227,294,373,467,576,703,849,1015,

%T 1203,1414,1652,1916,2209,2533,2890,3282,3710,4177,4684,5234,5829,

%U 6470,7161,7903,8698,9549,10458,11427,12458,13555,14719,15953,17259,18640,20098,21636,23257

%N a(n) = floor( Sum_{1 <= i < j <= n} ((sqrt(j)-sqrt(i))^3) ).

%K nonn

%O 2,4

%A _Clark Kimberling_

%E a(45) corrected by _Sean A. Irvine_, Aug 16 2019