The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A065422 If n|a(n) then a(n+1) = a(n)/(highest power of n that divides a(n)), otherwise a(n+1) = n*a(n); a(0) = 1. 3
 1, 1, 2, 6, 24, 120, 20, 140, 1120, 10080, 1008, 11088, 77, 1001, 14014, 210210, 3363360, 57177120, 1029188160, 19554575040, 977728752, 2217072, 100776, 2317848, 96577, 2414425, 62775050, 1694926350, 47457937800, 1376280196200 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS Reinhard Zumkeller, Table of n, a(n) for n = 0..1000 MATHEMATICA nxt[{n_, a_}]:={n+1, If[Divisible[a, n], a/n^IntegerExponent[a, n], a*n]}; Join[ {1, 1}, Transpose[NestList[nxt, {3, 2}, 30]][[2]]] (* Harvey P. Dale, Jan 08 2013 *) PROG (Haskell) a065422 n = a065422_list !! n a065422_list = 1 : 1 : f 2 1 where    f n x = x' : f (n+1) x' where        x' | x `mod` n == 0 = until ((> 0) . (`mod` n)) (`div` n) x           | otherwise      = x * n -- Reinhard Zumkeller, Oct 10 2011 CROSSREFS See A008336 for another version. Cf. A005132. Sequence in context: A092495 A110808 A284567 * A260850 A008336 A033643 Adjacent sequences:  A065419 A065420 A065421 * A065423 A065424 A065425 KEYWORD easy,nonn,nice,look AUTHOR Naohiro Nomoto, Nov 23 2001 EXTENSIONS Definition and offset corrected by Reinhard Zumkeller, Oct 10 2011 Typo in Crossrefs fixed by Paul Tek, Aug 01 2015 STATUS approved

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

Last modified August 8 19:29 EDT 2020. Contains 336298 sequences. (Running on oeis4.)