N.Y. Est. Powers & Trusts Law § 1-2.16

§ 1-2.16 Representation\n By representation means a disposition or distribution of property made\nin the following manner to persons who take as issue of a deceased\nancestor:\n The property so passing is divided into as many equal shares as there\nare (i) surviving issue in the generation nearest to the deceased\nancestor which contains one or more surviving issue and (ii) deceased\nissue in the same generation who left surviving issue, if any. Each\nsurviving member in such nearest generation is allocated one share. The\nremaining shares, if any, are combined and then divided in the same\nmanner among the surviving issue of the deceased issue as if the\nsurviving issue who are allocated a share had predeceased the decedent,\nwithout issue.\n