%I
%S 1,0,0,5,0,3,15,0,15,35,6,45,70,30,105,135,90,210,255,210,390,465,420,
%T 690,810,771,1170,1345,1335,1905,2153,2205,2985,3345,3495,4536,5060,
%U 5340,6720,7465,7920,9735,10755,11460,13815,15180,16230,19230,21045,22545
%N Number of n element multisets of the 15th roots of unity with zero sum.
%C Equivalently, the number of closed convex paths of length n whose steps are the 15th roots of unity up to translation.
%H Andrew Howroyd, <a href="/A321418/b321418.txt">Table of n, a(n) for n = 0..1000</a>
%F G.f.: (1  x^15)/((1  x^3)^5 * (1  x^5)^3).
%o (PARI) Vec((1  x^15)/((1  x^3)^5 * (1  x^5)^3) + O(x^50))
%Y Cf. A198805, A321419.
%K nonn,easy
%O 0,4
%A _Andrew Howroyd_, Nov 09 2018
