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%I #26 Dec 04 2024 17:50:29
%S 4,4,4,4,8,8,8,8,9,12,12,12,16,16,16,16,18,18,20,20,24,24,24,24,25,27,
%T 27,28,32,32,32,32,36,36,36,36,40,40,40,40,44,44,44,44,45,48,48,48,49,
%U 50,52,52,54,54,56,56,60,60,60,60,63,63,63,64,68,68,68,68,72,72,72,72
%N Smallest nonsquarefree number >= n.
%H Vincenzo Librandi, <a href="/A120327/b120327.txt">Table of n, a(n) for n = 1..1000</a>
%t Table[NestWhile[ #+1&,n,SquareFreeQ],{n,100}] (* simplified by _Harvey P. Dale_, Apr 08 2014 *)
%Y For squarefree instead of nonsquarefree we have A067535, differences A378087.
%Y The opposite for squarefree is A070321, differences A378085.
%Y The run-lengths are A078147 if we prepend 4, differences A376593.
%Y The restriction to primes is A377783 (union A378040), differences A377784.
%Y The opposite is A378033 (differences A378036), for prime powers A031218.
%Y First differences are A378039 if we assume that a(1) = 1.
%Y A005117 lists the squarefree numbers.
%Y A013929 lists the nonsquarefree numbers.
%Y A061398 counts squarefree numbers between primes, zeros A068360.
%Y A061399 counts nonsquarefree numbers between primes, zeros A068361.
%Y Restriction to primes: A112925, A112926, A337030, A378032, A378034, A378037, A378038, A378082, A378084.
%Y Cf. A000015, A007675, A013928, A053797, A053806, A068781, A072284, A073247, A120992, A224363.
%K nonn
%O 1,1
%A _Zak Seidov_, Aug 16 2006