Codes and L(2,1)-labelings in Sierpiński graphsGravier, Sylvain (Avtor) Klavžar, Sandi (Avtor) Mollard, Michel (Avtor) matematikateorija grafov▫$L(21)$▫-označitev▫$lambda$▫-številografovske kodepopolne kodegrafi Sierpińskegamathematicsgraph theory▫$L(21)▫$-labelings▫$lambda$▫-numbercodes in graphsperfect codesSierpiński graphsThe ▫$lambda$▫-number of a graph ▫$G$▫ is the minimum value ▫$lambda$▫ such that ▫$G$▫ admits a labeling with labels from ▫${0, 1,..., lambda}$▫ where vertices at distance two get different labels and adjacent vertices get labels that are at least two apart. Sierpiński graphs ▫$S(n,k)$▫ generalize the Tower of Hanoi graphs - the graph ▫$S(n,3)$▫ is isomorphic to the graph of the Tower of Hanoi with ▫$n$▫ disks. It is proved that for any ▫$n ge $▫2 and any ▫$k ge 3$▫, ▫$lambda (S(n,k)) = 2k$▫. To obtain the result (perfect) codes in Sierpiński graphs are studied in detail. In particular a new proof of their (essential) uniqueness is obtained. 20052015-07-10 14:52:48Članek v reviji51513sl