A304087 Divisor-or-multiple permutation of squarefree numbers: a(n) = A019565(A304083(n)).

1, 2, 6, 3, 30, 15, 5, 10, 210, 105, 35, 7, 70, 14, 42, 21, 2310, 1155, 385, 77, 11, 770, 154, 22, 462, 231, 33, 330, 165, 55, 110, 30030, 66, 6006, 3003, 1001, 143, 13, 15015, 5005, 715, 65, 10010, 2002, 286, 26, 4290, 2145, 429, 39, 858, 78, 2730, 1365, 455, 91, 910, 182, 546, 273, 510510, 1430, 130, 390, 195, 255255, 85085, 17017, 2431, 221, 17, 170170

Offset: 0

Author

Antti Karttunen, May 06 2018

Keywords

• nonn

Comments

Each a(n+1) is either a divisor or a multiple of a(n).

Links

• Antti Karttunen, Table of n, a(n) for n = 0..8191

Crossrefs

Cf. A019565, A304083, A304085.

Cf. also A303778.

Programs

PARI

A019565(n) = {my(j,v); factorback(Mat(vector(if(n, #n=vecextract(binary(n), "-1..1")), j, [prime(j), n[j]])~))}; \\ From A019565
A304087(n) = A019565(A304083(n)); \\ Needs also code from A304083.

Formula

a(n) = A019565(A304083(n)).