A086357 Fixed point if [nonzero-digit-product]-function at initial-value=A002110(n)=n-th primorial is iterated.

2, 6, 3, 2, 6, 9, 1, 6, 8, 2, 8, 8, 8, 8, 6, 8, 6, 7, 8, 2, 8, 8, 8, 6, 2, 8, 1, 6, 8, 2, 2, 2, 8, 6, 8, 8, 8, 6, 4, 6, 2, 8, 2, 6, 6, 2, 2, 2, 6, 6, 8, 6, 2, 8, 8, 8, 5, 8, 6, 8, 2, 8, 8, 1, 2, 2, 8, 6, 8, 2, 2, 8, 2, 8, 8, 2, 2, 8, 8, 9, 6, 8, 4, 6, 8, 8, 8, 2, 8, 6, 8, 1, 6, 2, 2, 8, 1, 6, 6, 8, 6, 9, 2, 6, 2

Offset: 1

Author

Labos Elemer, Jul 21 2003

Keywords

• base
• nonn

Examples

			n=7, 7th-primorial=510510, iteration list={510510,25,10,1},
a(100)=2.
		

Crossrefs

Cf. A051801, A051802, A086353-A086361, A029898, A010888, A038194, A000984.

Programs

Mathematica

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

Formula

a(n)=A051802[A002110(n)]=fixed-point of A051801[A002110(n)]