A075429 First integer reached when starting with 1+2/(n*(n+1)) and iterating the map x -> x*ceiling(x) A075428(n) times, or -1 if no integer is ever reached.

2, 8, 7, 494764640798827359861461484, 2016, 44, 1914, 28763295962709272528037893195870015938157927816600800, 135182360017670059436612452

Offset

1,1

Links

Table of n, a(n) for n=1..9.

Example

n=5: after A075428(5)=4 steps 1+2/(5*6)=1+1/15=16/15 -> 32/15 -> 32/5 -> 224/5 -> 2016, therefore a(5)=2016.

Crossrefs

Sequence in context: A303498 A166539 A344718 * A344692 A256166 A021976

Adjacent sequences: A075426 A075427 A075428 * A075430 A075431 A075432

Keyword

nonn

Author

Reinhard Zumkeller, Sep 16 2002

Status

approved