A083863 Consider recurrence b(0) = n/3, b(n) = b(n-1)*floor(b(n-1)); sequence gives first integer reached, or -1 if no integer is ever reached.

2, 336, 480480, 3, 10, 11, 4, 86632, 336, 5, 480480, 602088585139494925392355287938913017768414449509198770325691172429632961571366883360109083120, 6, 38, 40, 7, 2618, 8089284, 8, 4400, 4784, 9, 84, 87, 10, 164651957685772369755334525952840, 267038744632379007295584790187520, 11, 3260628657396881107663076132351728

Offset

6,1

Comments

It is conjectured that an integer is always reached if the initial value is >= 2.

Links

Table of n, a(n) for n=6..34.

J. C. Lagarias and N. J. A. Sloane, Approximate squaring (pdf, ps), Experimental Math., 13 (2004), 113-128.

Crossrefs

Cf. A087666 (steps to reach an integer), A086336, A087663.

Sequence in context: A203608 A264942 A159488 * A246872 A057626 A201310

Adjacent sequences: A083860 A083861 A083862 * A083864 A083865 A083866

Keyword

nonn

Author

N. J. A. Sloane, Sep 27 2003

Status

approved