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A116046
n+phi(n)+phi(phi(n)) is a semiprime (A001358).
1
2, 3, 6, 7, 8, 11, 14, 18, 23, 27, 29, 31, 34, 37, 38, 42, 45, 47, 53, 55, 59, 63, 65, 66, 69, 73, 74, 83, 89, 90, 91, 93, 103, 105, 107, 109, 110, 117, 119, 123, 125, 127, 129, 130, 131, 138, 139, 143, 145, 150, 151, 157, 167, 174, 175, 179, 182, 183, 185, 186
OFFSET
1,1
EXAMPLE
103+phi(103)+phi(phi(103)) = 3*79.
CROSSREFS
Sequence in context: A304028 A155152 A098740 * A069579 A327176 A065193
KEYWORD
nonn
AUTHOR
Giovanni Resta, Feb 13 2006
STATUS
approved