A167748 phi((n!!)!)

1, 1, 2, 9216, 250822656000, 1721860898320750629665025350129266874199532634112000000000000, 127571798940158944523056860801259448502131218787316228449430227816121623349001793754442941084615568218917882938952698416464702214493962240000000000000000000000000000000

Offset

1,3

Comments

Next term has 827 digits.

Links

Table of n, a(n) for n=1..7.

Mathematica

Table[EulerPhi[n!!! ], {n, 7}]

Crossrefs

Sequence in context: A171939 A104904 A272247 * A203755 A285692 A340546

Adjacent sequences: A167745 A167746 A167747 * A167749 A167750 A167751

Keyword

nonn

Author

Vladimir Joseph Stephan Orlovsky, Nov 10 2009

Extensions

Corrected by Charles R Greathouse IV, Nov 12 2009

Status

approved