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.

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

Offset

0,3

Links

Reinhard Zumkeller, Table of n, a(n) for n = 0..1000

Index entries for sequences related to Recamán's sequence

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: A369407 A284567 A360300 * A260850 A008336 A360298

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