

A066616


a(1) = 1; a(n) = n*a(n1) if n does not divide a(n1), otherwise a(n) = a(n1).


3



1, 2, 6, 24, 120, 120, 840, 840, 7560, 7560, 83160, 83160, 1081080, 1081080, 1081080, 17297280, 294053760, 294053760, 5587021440, 5587021440, 5587021440, 5587021440, 128501493120, 128501493120, 3212537328000, 3212537328000
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OFFSET

1,2


LINKS



FORMULA



EXAMPLE

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).


MATHEMATICA

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 *)


PROG

(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


CROSSREFS



KEYWORD

nonn


AUTHOR



EXTENSIONS



STATUS

approved



