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A207667
Numbers n such that phi(n) divides n+2.
1
1, 2, 4, 6, 10, 30, 70, 510, 2590, 131070, 3359230, 167247870, 8589934590, 13985925344264190
OFFSET
1,2
COMMENTS
Contains 2 * A203966 as a subsequence. - Max Alekseyev, Oct 27 2023
MATHEMATICA
Select[Range[50000000], Divisible[#+2, EulerPhi[#]]&]
CROSSREFS
KEYWORD
nonn,more,hard
AUTHOR
EXTENSIONS
a(12)-a(13) from Donovan Johnson, Mar 01 2012
a(14) from Max Alekseyev, Oct 27 2023
STATUS
approved