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

1,2

Links

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

Formula

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

Example

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

Maple

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

Prog

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

Crossrefs

Cf. A002322.

Cf. A010052.

Sequence in context: A101725 A274453 A105370 * A190459 A135042 A109666

Adjacent sequences: A173691 A173692 A173693 * A173695 A173696 A173697

Keyword

nonn

Author

Michel Lagneau, Nov 25 2010

Extensions

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

Status

approved