A120327 Smallest nonsquarefree number >= n.

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, 27, 28, 32, 32, 32, 32, 36, 36, 36, 36, 40, 40, 40, 40, 44, 44, 44, 44, 45, 48, 48, 48, 49, 50, 52, 52, 54, 54, 56, 56, 60, 60, 60, 60, 63, 63, 63, 64, 68, 68, 68, 68, 72, 72, 72, 72

Offset

1,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Mathematica

Table[NestWhile[ #+1&, n, SquareFreeQ], {n, 100}] (* simplified by Harvey P. Dale, Apr 08 2014 *)

Crossrefs

For squarefree instead of nonsquarefree we have A067535, differences A378087.

The opposite for squarefree is A070321, differences A378085.

The run-lengths are A078147 if we prepend 4, differences A376593.

The restriction to primes is A377783 (union A378040), differences A377784.

The opposite is A378033 (differences A378036), for prime powers A031218.

First differences are A378039 if we assume that a(1) = 1.

A005117 lists the squarefree numbers.

A013929 lists the nonsquarefree numbers.

A061398 counts squarefree numbers between primes, zeros A068360.

A061399 counts nonsquarefree numbers between primes, zeros A068361.

Restriction to primes: A112925, A112926, A337030, A378032, A378034, A378037, A378038, A378082, A378084.

Cf. A000015, A007675, A013928, A053797, A053806, A068781, A072284, A073247, A120992, A224363.

Sequence in context: A240835 A047210 A360915 * A056629 A245356 A167185

Adjacent sequences: A120324 A120325 A120326 * A120328 A120329 A120330

Keyword

nonn

Author

Zak Seidov, Aug 16 2006

Status

approved