This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A375514 #15 Aug 28 2024 11:28:19 %S A375514 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 A375514 60,61,62,66,67,68,69,74,77,78,82,83,84,85,88,90,92,93,94,98,104,106, %U A375514 110,114,115,122,123,126,130,131,132,133,138,139,140,141,142,146 %N A375514 Numbers k such that floor((k^3 - k)/4) is squarefree. %t A375514 Select[Range[150],SquareFreeQ[Floor[(#^3-#)/4]] &] (* _Stefano Spezia_, Aug 19 2024 *) %o A375514 (Magma) [k: k in [2..150] | IsSquarefree(Floor((k^3-k) div 4))]; %Y A375514 Supersequence of A179017 and A269844. %Y A375514 Cf. A005117. %K A375514 nonn %O A375514 1,1 %A A375514 _Juri-Stepan Gerasimov_, Aug 18 2024