A087710 Least k >= 6 such that A087666(k) = n.

6, 10, 14, 7, 8, 31, 35, 17, 43, 40, 229, 248, 212, 818, 799, 733, 151, 2191, 1139, 20894, 877, 6835, 20528, 34627, 19687, 91790, 34502, 367558, 85336, 46375, 1342349, 134683, 109057, 2758327, 5921086, 1655564, 18147329, 11934733, 1315376, 1463921, 39945479

Offset

0,1

Comments

A087666: Consider the recurrence b(0) = n/3, b(n) = b(n-1)*floor(b(n-1)); sequence gives number of steps to reach an integer, or -1 if no integer is ever reached. - Robert G. Wilson v, Oct 10 2003 & Mar 10 2004

Links

Chai Wah Wu, Table of n, a(n) for n = 0..60

Maple

See the Maple program in A087666 for the best way to compute this sequence. - N. J. A. Sloane

Mathematica

f[n_] := Block[{c = 1, k = n/3}, If[ IntegerQ[k], 0, While[tn = Floor[k]; tf = k - tn; tn = Mod[tn, 3^100]; k = tn(tn + tf); ! IntegerQ[k], c++ ]; c++ ]]; a = Table[0, {50}]; Do[ b = f[n]; If[ a[[b + 1]] == 0, a[[b + 1]] = n; Print[b, " = ", n]], {n, 6, 10^7}]; a (* Robert G. Wilson v, Mar 10 2004, using the idea from N. J. A. Sloane's Maple code in A087666 *)

Crossrefs

Cf. A087666, A086336, A087663.

Sequence in context: A163814 A395578 A088706 * A163504 A129146 A315158

Adjacent sequences: A087707 A087708 A087709 * A087711 A087712 A087713

Keyword

nonn

Author

Benoit Cloitre, Sep 30 2003

Extensions

More terms from Robert G. Wilson v, Oct 10 2003, Mar 10 2004

Status

approved