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%I #9 Jul 02 2022 15:29:07
%S 1,2,3,4,10,12,7,8,9,10,11,12,26,56,15,16,17,18,19,20,21,22,69,24,50,
%T 52,27,28,29,30,31,64,33,34,35,36,37,76,39,40,82,84,43,44,45,46,47,48,
%U 49,100,51,52,53,54,55,56,57,58,177,60,122,124,63,64,65,66,67,136,69,70,71
%N Smallest multiple of n such that a(n) + a(n-1) is a squarefree number.
%C The sequence ends with a(319)=1276, since 320k + 1276 is divisible by 4 for all k.
%t smn[{n_,a_}]:=Module[{k=1},While[!SquareFreeQ[a+k*n],k++];{n+1,k*n}]; NestList[ smn,{1,1},80][[All,2]] (* _Harvey P. Dale_, Jul 02 2022 *)
%K fini,nonn
%O 1,2
%A _Jason Earls_ and _Amarnath Murthy_, Jul 18 2003
%E Edited by _Dean Hickerson_, Jul 20 2003