A325625 - OEIS

A325625

Sorted prime signature of 2^n - 1.

1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 2, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1

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OFFSET

1,8

COMMENTS

The sorted prime signature of n is row n of A124010.

LINKS

Table of n, a(n) for n=1..87.

EXAMPLE

We have 2^126 - 1 = 3^3 * 7^2 * 19 * 43 * 73 * 127 * 337 * 5419 * 92737 * 649657 * 77158673929, so row n = 126 is {1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 3}.

Triangle begins:

1 1

1 2

1 1 1

1 1

1 1 1

1 1

1 1 1 2

1 1 1

1 1 1 1

1 1 1 3

1 1 1 1 2

MATHEMATICA

Table[Sort[Last/@FactorInteger[2^n-1]], {n, 30}]

CROSSREFS

Cf. A001222, A056239, A067255, A071625, A112798, A118914, A124010.

Mersenne numbers: A046051, A046800, A059305, A325610, A325611, A325612.

Sequence in context: A270419 A275216 A062379 * A043288 A353786 A057523

Adjacent sequences: A325622 A325623 A325624 * A325626 A325627 A325628

KEYWORD

nonn,tabf

AUTHOR

Gus Wiseman, May 13 2019

STATUS

approved