A087677 Consider recurrence b(0) = n/3, b(n) = b(0)*floor(b(n-1)); sequence gives first integer reached, or -1 if no integer is ever reached.

2, 21, 240, 3, 10, 11, 4, 170195636, 84, 5, 736, 922709, 6, 38, 40, 7, 374, 10751097, 8, 550, 598, 9, 84, 87, 10, 1173908, 1371360, 11, 262696240, 203210, 12, 148, 152, 13, 72879280, 2419, 14, 588799, 44088, 15, 230, 235, 16, 4263, 20523050, 17, 5096, 5300, 18, 330, 336

Offset: 6

Author

N. J. A. Sloane, following a suggestion of Bela Bajnok (bbajnok(AT)gettysburg.edu), Sep 27 2003

Keywords

• nonn

Comments

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

Links

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

Crossrefs

Cf. A087675, A087676.