0,4

a(n) = floor(n*ln(3)/ln(10)) + 1. E.g. a(10)=5 because 3^10=59049 and floor(10*ln(3)/ln(10)+1=4+1=5. - Jaap Spies (j.spies(AT)hccnet.nl), Dec 15 2003

seq(floor(n*ln(3)/ln(10))+1, n=0..100);

Sequence in context: A135020 A072921 A140106 this_sequence A086388 A080513 A111660

Adjacent sequences: A034885 A034886 A034887 this_sequence A034889 A034890 A034891

nonn,base,easy

njas