The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
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!)
A066616 a(1) = 1; a(n) = n*a(n-1) if n does not divide a(n-1), otherwise a(n) = a(n-1). 3

%I #16 Jul 12 2022 14:36:04

%S 1,2,6,24,120,120,840,840,7560,7560,83160,83160,1081080,1081080,

%T 1081080,17297280,294053760,294053760,5587021440,5587021440,

%U 5587021440,5587021440,128501493120,128501493120,3212537328000,3212537328000

%N a(1) = 1; a(n) = n*a(n-1) if n does not divide a(n-1), otherwise a(n) = a(n-1).

%H Harry J. Smith, <a href="/A066616/b066616.txt">Table of n, a(n) for n = 1..200</a>

%F a(1) = 1; for n > 1, a(n) = A059896(a(n-1), n). - _Peter Munn_, Jul 12 2022

%e a(5) = 120; as 6 divides a(5), we have a(6) = a(5) = 120. Though 9 is not coprime to a(8) but still 9 does not divide a(8) so a(9) = 9 * a(8).

%t nxt[{n_,a_}]:={n+1,If[Mod[a,n+1]==0,a,a(n+1)]}; NestList[nxt,{1,1},30][[All,2]] (* _Harvey P. Dale_, Jul 01 2022 *)

%o (PARI) { for (n=1, 200, if (n==1, a=1, if (a%n, a=n*a)); write("b066616.txt", n, " ", a) ) } \\ _Harry J. Smith_, Mar 12 2010

%Y Cf. A003418, A037992 (duplicates removed).

%Y Replacing A059896 with A059897 in the formula gives A284567.

%K nonn

%O 1,2

%A _Amarnath Murthy_, Dec 24 2001

%E More terms from _Vladeta Jovovic_, Dec 26 2001

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 May 15 14:34 EDT 2024. Contains 372540 sequences. (Running on oeis4.)