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A055971
Numbers n such that n | (sigma(n) - d(n) - phi(n)) and n is not a prime or twice a prime.
1
1, 198, 294, 20280, 195320, 1782240, 3038720, 12190720
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OFFSET
1,2
LINKS
Table of n, a(n) for n=1..8.
MATHEMATICA
Do[ If[ And[ !PrimeQ[ n ], !PrimeQ[ n/2 ] ], If[ Mod[ DivisorSigma[ 1, n ]-DivisorSigma[ 0, n ]- EulerPhi[ n ], n ]==0, Print[ n ] ] ], {n, 1, 10^8} ]
CROSSREFS
Cf.
A000005
(d(n)),
A000010
(phi),
A000203
(sigma).
Sequence in context:
A248534
A334403
A238230
*
A075293
A083264
A202526
Adjacent sequences:
A055968
A055969
A055970
*
A055972
A055973
A055974
KEYWORD
easy
,
nonn
AUTHOR
Robert G. Wilson v
, Jul 19 2000
STATUS
approved
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Last modified March 28 18:04 EDT 2024. Contains 371254 sequences. (Running on oeis4.)