A085330 Where records occur in A085068.

0, 1, 5, 161, 1772, 3097, 3473, 23084, 38752, 335165, 491729, 38248700, 49050536, 95305397, 1019659805, 1549919921, 2973640172, 4527000701, 6300121204, 10663850980, 30980417576, 40783699961, 57033894608, 409565230433

Offset: 1

Author

N. J. A. Sloane, Aug 13 2003

Keywords

• nonn
• more

Links

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

Crossrefs

Cf. A085068, A085071, A085328.

Programs

Mathematica

f[n_] := Block[{c = 1, k = 4 n/3}, While[ ! IntegerQ@k, c++; k = 4 Ceiling@k/3]; c]; t = Table[0, {1000}]; Do[ a = f@n; If[a < 101 && t[[a]] == 0, t[[a]] = n; Print[{a, n}]], {n, 0, 21*10^8}] (* Robert G. Wilson v, May 28 2007 *)

PARI

f(n)=(4/3)*ceil(n); { a(n) = local(c, k); c=1; k=n; while(frac(f(k))!=0, k=f(k); c++); c } { rec=0; for(n=0,5*10^5,if(a(n)>rec,rec=a(n); print1(n":"a(n)","))) }

Extensions

More terms from Jason Earls, Aug 14 2003

a(12)-a(16) from Robert G. Wilson v, May 28 2007

a(17)-a(24) from Lars Blomberg, Mar 03 2018