关于CalMekes和多边形数、伯努利多项式和Base-P数字的和,ARXIV:1902.10672 [数学,NT ],2019。%%H A324972维基百科,多边形数%F A324972 Squarefree P(s,n) = (n^2*(s-2)-n*(s-4))/2 with s >= 3 and n >= 3.
%e A324972 P(3,3) = 6 which is squarefree, so a(1) = 6.
%t A324972 mx = 250; n = s = 3; lst = {};
%t A324972 While[s < Floor[mx/3] + 2, a = (n^2 (s - 2) - n (s - 4))/2;
%t A324972 If[a < mx + 1, AppendTo[lst, a], (s++; n = 2)]; n++]; lst = Union@lst;
%t A324972 Select[lst, SquareFreeQ]
%o A324972 (PARI) isok(n) = if (!3月24日A416917和A090466交会的A324972,包括AA24997,A324972,AN 249972,NN,%A324972,A324972,1,1%,A324972,BELND C.KELNELNY和Y-JONATON SONDOWAY,3月21日2019π的内容在OEIS最终用户许可协议下可用:HTTP:/OEIS.Org/许可证ISS(n),返回(0);(s=3,n=3+1,等多边形(n,s)