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A116006
n*phi(n)*phi(phi(n)) is a triangular number.
0
1, 3, 42, 77, 1517, 4238484
OFFSET
1,2
EXAMPLE
1517*phi(1517)*phi(phi(1517))=T(40959).
CROSSREFS
Cf. A116002.
Sequence in context: A055755 A249046 A237661 * A079826 A112291 A063040
KEYWORD
nonn
AUTHOR
Giovanni Resta, Feb 13 2006
STATUS
approved