A173694 Arguments n for which the Carmichael lambda function A002322(n) is a perfect square.

1, 2, 5, 10, 15, 16, 17, 20, 30, 34, 37, 40, 48, 51, 60, 64, 68, 74, 80, 85, 95, 101, 102, 111, 120, 125, 135, 136, 148, 170, 185, 190, 192, 197, 202, 204, 222, 240, 247, 250, 255, 256, 257, 259, 270, 272, 285, 296, 303, 304, 320, 323, 333, 340, 351, 370, 375, 380, 394, 401

Offset: 1

Author

Michel Lagneau, Nov 25 2010

Keywords

• nonn

Examples

			37 is in the sequence because lambda(37) = 36 = 6^2.
		

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A002322.

Cf. A010052.

Programs

Haskell

a173694 n = a173694_list !! (n-1)
a173694_list = filter ((== 1) . a010052 . a002322) [1..]
-- Reinhard Zumkeller, Sep 02 2014

Maple

for n from 1 to 500 do if issqr(numtheory[lambda](n) ) then printf("%d,",n) ;     end if; end do:

Formula

A010052(A002322(a(n))) = 1. - Reinhard Zumkeller, Sep 02 2014

Extensions

Definition rephrased - R. J. Mathar, Nov 26 2010