login
This site is supported by donations to The OEIS Foundation.

 

Logo

Invitation: celebrating 50 years of OEIS, 250000 sequences, and Sloane's 75th, there will be a conference at DIMACS, Rutgers, Oct 9-10 2014.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A173694 Arguments n for which the Carmichael lambda function A002322(n) is a perfect square. 1
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 (list; graph; refs; listen; history; text; internal format)
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: A064955 A101725 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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified October 1 02:09 EDT 2014. Contains 247498 sequences.