A303770 Divisor-or-multiple permutation of squarefree numbers: a(n) = A019565(A303773(n)).

1, 2, 6, 3, 15, 5, 10, 30, 210, 42, 21, 7, 14, 70, 35, 105, 1155, 165, 55, 11, 22, 66, 33, 231, 77, 154, 462, 2310, 330, 110, 770, 385, 5005, 455, 91, 13, 26, 78, 39, 195, 65, 130, 390, 2730, 182, 546, 273, 1365, 15015, 3003, 429, 143, 286, 858, 4290, 1430, 715, 2145, 36465, 561, 51, 17, 34, 102, 510, 170, 85, 255, 1785, 357, 119, 238, 714

Offset: 0

Author

Antti Karttunen, May 05 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..10092

Crossrefs

Cf. A005117, A019565, A303773.

Cf. A303760 (a simpler variant).

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
A303770(n) = A019565(A303773(n)); \\ Uses also code from A303773.

Formula

a(n) = A019565(A303773(n)).