A258781 a(n) is the greatest positive integer k such that lambda(k) <= n where lambda is the Carmichael lambda function (A002322).

2, 24, 24, 240, 240, 504, 504, 504, 504, 504, 504, 65520, 65520, 65520, 65520, 65520, 65520, 65520, 65520, 65520, 65520, 65520, 65520, 131040, 131040, 131040, 131040, 131040, 131040, 171864, 171864, 171864, 171864, 171864, 171864, 138181680, 138181680, 138181680

Offset

1,1

Links

Table of n, a(n) for n=1..38.

Eric W. Weisstein's mathWorld, Carmichael Function

Example

a(2)=24 because lambda(24) = 2 and 24 is the greatest number such that lambda(24) <= 2.

Maple

with(numtheory):
for n from 1 to 30 do:
  ii:=0:
   for k from 10^7 by -1 to 1 while(ii=0)do:
   if lambda(k)<=n
   then
   printf(`%d, `, k):ii:=1:
   else
   fi:
  od:
od:

Crossrefs

Cf. A002322, A253215.

Sequence in context: A229429 A281139 A052686 * A371207 A064818 A349724

Adjacent sequences: A258778 A258779 A258780 * A258782 A258783 A258784

Keyword

nonn

Author

Michel Lagneau, Jun 10 2015

Extensions

a(36)-a(38) corrected by Seth A. Troisi, Nov 22 2015

Status

approved