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A207574
Numbers k such that phi(k)+2 divides k+2.
4
1, 6, 10, 14, 22, 26, 34, 38, 46, 58, 62, 74, 82, 86, 94, 106, 118, 122, 134, 142, 146, 158, 166, 178, 194, 202, 206, 214, 218, 226, 254, 262, 274, 278, 298, 302, 314, 326, 334, 346, 358, 362, 382, 386, 390, 394, 398, 422, 446, 454, 458, 466, 478
OFFSET
1,2
COMMENTS
Consists of the even semiprimes (other than 4) together with A207575. - Charles R Greathouse IV, Jul 15 2013
LINKS
MATHEMATICA
Select[Range[1000], Divisible[#+2, EulerPhi[#]+2]&]
PROG
(PARI) isA207574(n)={
if( (n+2) % (eulerphi(n)+2) ==0, 1, 0) ;
}
{
for(n=1, 200,
if (isA207574(n) , print(n)) ;
) ;
} /* R. J. Mathar, Feb 23 2012 */
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved