A086361 -id:A086361 - cp's OEIS frontend

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

Labos Elemer, Jul 21 2003

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

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

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}]

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

A086359 Fixed point if [decimal-digit-sum]-function at initial-value=A000984(n)=C[2n,n] is iterated.

Original entry on oeis.org

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

Offset: 1

Labos Elemer, Jul 21 2003

			n=10, C[20,10]=184756, iteration list={184756,31,4},a(10)=4.

Cf. A086353-A086361, A007953, A010888, A038194, A029898.

sud[x_] := Apply[Plus, DeleteCases[IntegerDigits[x], 0]] Table[FixedPoint[sud, Binomial[2*w, w]], {w, 1, 128}]

a(n)=A010888[C[2n, n]]=fixed-point of A007953[C[2n, n]]; It equals C[2n, n] modulo(9); at r=0 use 9.

cp's OEIS Frontend

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

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