Number of lucky 2,6 triples <= 10^n.A055726Number of lucky 2,6 triples <= 10^n.Terms a(0) =1a(1) =2a(2) =5a(3) =16a(4) =52a(5) =243a(6) =1374a(7) =8503a(8) =55537External referencesoeis: A055726