A282631 - OEIS

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A282631

The smallest square referenced in A237043 (Numbers n such that 2^n - 1 is not squarefree, but 2^d - 1 is squarefree for every proper divisor d of n.).

9, 25, 49, 121, 289, 961, 529, 1194649, 1849, 5329, 841, 16129, 7921, 2209

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Table of n, a(n) for n=1..14.

EXAMPLE

A237043(1)=6, 2^6-1=63, 63=3*3*7, 63 is not squarefree and the square is 3*3=9.

CROSSREFS

Cf. A237043, A282632.

Sequence in context: A110284 A109367 A110588 * A245694 A045972 A297596

Adjacent sequences: A282628 A282629 A282630 * A282632 A282633 A282634

KEYWORD

nonn,more

AUTHOR

Robert Price, Feb 19 2017

STATUS

approved