login
Numbers k such that floor((k^3 - k)/4) is squarefree.
0

%I #15 Aug 28 2024 11:28:19

%S 2,3,4,5,10,11,12,13,14,18,20,21,26,29,30,34,40,42,43,46,50,52,56,59,

%T 60,61,62,66,67,68,69,74,77,78,82,83,84,85,88,90,92,93,94,98,104,106,

%U 110,114,115,122,123,126,130,131,132,133,138,139,140,141,142,146

%N Numbers k such that floor((k^3 - k)/4) is squarefree.

%t Select[Range[150],SquareFreeQ[Floor[(#^3-#)/4]] &] (* _Stefano Spezia_, Aug 19 2024 *)

%o (Magma) [k: k in [2..150] | IsSquarefree(Floor((k^3-k) div 4))];

%Y Supersequence of A179017 and A269844.

%Y Cf. A005117.

%K nonn

%O 1,1

%A _Juri-Stepan Gerasimov_, Aug 18 2024