A universal sequence of integers generating balanced Steinhaus figures modulo an odd number

In this paper we partially solve an open problem due to JC Molluzzo in 1976 on the existence of balanced Steinhaus triangles modulo a positive integer n that are Steinhaus triangles containing all the elements of Z/nZ with the same multiplicity For every odd number n we build an orbit in Z/nZ by the linear cellular automaton generating the Pascal triangle modulo n, which contains infinitely many balanced Steinhaus triangles This orbit in Z/nZ, is obtained from an integer sequence called the universal sequence We show that there exist balanced Steinhaus triangles for at least 2/3 of the admissible sizes in the case where n is an odd prime power Other balanced Steinhaus figures such as Steinhaus trapezoids generalized Pascal mangles Pascal trapezoids or lozenges also appear in the orbit of the universal sequence modulo n odd We prove the existence of balanced generalized Pascal triangles for at least 2/3 of the admissible sizes in the case where n is an odd prime power and the existence of balanced lozenges for all admissible sizes in the case where n is a square-free odd number (C) 2010 Elsevier Inc All rights reserved