A086353 Fixed point if nonzero-digit product of n! is iterated.

1, 2, 6, 8, 2, 4, 2, 8, 8, 8, 6, 1, 2, 8, 8, 8, 8, 6, 8, 8, 8, 8, 8, 2, 2, 8, 4, 8, 6, 2, 2, 6, 1, 8, 8, 8, 2, 2, 6, 8, 8, 8, 8, 8, 8, 6, 8, 6, 8, 8, 8, 6, 6, 1, 8, 8, 5, 8, 6, 6, 8, 6, 8, 2, 8, 8, 8, 6, 8, 2, 8, 8, 2, 6, 6, 8, 9, 6, 8, 8, 6, 2, 2, 8, 8, 8, 8, 4, 6, 8, 9, 6, 2, 2, 8, 2, 8, 8, 4, 4, 8, 8, 6, 2, 8

Offset: 1

Author

Labos Elemer, Jul 21 2003

Keywords

• base
• nonn

Examples

			n=10, 10!=362880, iteration list={3628800,2304,24,8},a(10)=8.
		

Crossrefs

Cf. A051801, A051802, A086354-A086361, A029898, A010888.

Programs

Mathematica

prd[x_] := Apply[Times, DeleteCases[IntegerDigits[x], 0]] Table[FixedPoint[prd, w! ], {w, 1, 128}]

Formula

a(n)=A051802[n! ]=fixed-point of A051801[n! ]