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A084694 Squarefree numbers which are products of three consecutive numbers. I.e., squarefree numbers of the form k^3 - k. 1

%I #15 Feb 25 2021 08:30:33

%S 6,210,2730,10626,26970,39270,54834,74046,195054,287430,342930,474474,

%T 635970,830490,1061106,1190910,1330890,1481430,2196870,2627934,

%U 2863146,3944154,4574130,5639574,6028386,6434670,7301190,8242206,9260790

%N Squarefree numbers which are products of three consecutive numbers. I.e., squarefree numbers of the form k^3 - k.

%C No product of 4 consecutive numbers is squarefree.

%H Amiram Eldar, <a href="/A084694/b084694.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = A007531(A007675(n)+2). - _Amiram Eldar_, Feb 25 2021

%t f[n_] := n*(n + 1)*(n + 2); f /@ Select[Range[250], AllTrue[# + {0, 1, 2}, SquareFreeQ] &] (* _Amiram Eldar_, Feb 25 2021 *)

%o (PARI) lista(nn) = {for (k=1, nn, if (issquarefree(x=k^3-k), print1(x, ", ")););} \\ _Michel Marcus_, Jul 29 2017

%Y Cf. A005117, A007531, A007675.

%K nonn

%O 1,1

%A _Amarnath Murthy_, Jun 04 2003

%E Offset corrected to 1 by _Michel Marcus_, Jul 29 2017

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Last modified May 25 12:29 EDT 2024. Contains 372788 sequences. (Running on oeis4.)