login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A304087 Divisor-or-multiple permutation of squarefree numbers: a(n) = A019565(A304083(n)). 4

%I #6 May 12 2018 14:44:54

%S 1,2,6,3,30,15,5,10,210,105,35,7,70,14,42,21,2310,1155,385,77,11,770,

%T 154,22,462,231,33,330,165,55,110,30030,66,6006,3003,1001,143,13,

%U 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

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

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

%H Antti Karttunen, <a href="/A304087/b304087.txt">Table of n, a(n) for n = 0..8191</a>

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

%o (PARI)

%o A019565(n) = {my(j,v); factorback(Mat(vector(if(n, #n=vecextract(binary(n), "-1..1")), j, [prime(j), n[j]])~))}; \\ From A019565

%o A304087(n) = A019565(A304083(n)); \\ Needs also code from A304083.

%Y Cf. A019565, A304083, A304085.

%Y Cf. also A303778.

%K nonn

%O 0,2

%A _Antti Karttunen_, May 06 2018

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified June 29 13:31 EDT 2024. Contains 373850 sequences. (Running on oeis4.)