Search: id:A097002 Results 1-1 of 1 results found. %I A097002 %S A097002 1,3,7,15,31,63,127,255,511,1023,2047,4095,8191,6045,24552,65535,131071, %T A097002 262143,524287,1048575,2097151,4194303,8388607,16777215,33554431, %U A097002 67108863,134217727,268435455,536870911,1073741823 %N A097002 A062402(x)=sigma(phi[x]) function is iterated; initial value=2^n; a(n)=smallest term of trajectory. %e A097002 n=13: 2^n=8192, trajectory ={8192, 8191, 26208, [20440], 20440, .. a[13]=8191 arose in transient. %t A097002 gf[x_] :=DivisorSigma[1, EulerPhi[x]] gite[x_, hos_] :=NestList[gf, x, hos] Table[Min[gite[2^w, 200]], {w, 1, 30}] %Y A097002 Cf. A000010, A000203, A062402, A096857. %Y A097002 Sequence in context: A043755 A105755 A043764 this_sequence A060152 A168604 A126646 %Y A097002 Adjacent sequences: A096999 A097000 A097001 this_sequence A097003 A097004 A097005 %K A097002 nonn %O A097002 1,2 %A A097002 Labos E. (labos(AT)ana.sote.hu), Jul 21 2004 Search completed in 0.001 seconds