来自在线整数百科全书的问候语!http://oeis.org/ Search: id:a205569 Showing 1-1 of 1 %I A205569 %S A205569 1,2,6,30,216,1930,20400,251174,3541888,56226258,991514880, %T A205569 19230159982,406873353216,9326318738906,230222431688704, %U A205569 6089006394645750,171780282479247360,5149076226504182434,163421449125050253312,5474820500060681776574 %N A205569 E.g.f.: 1/(1+x^2 - 2*x*cosh(x)). %C A205569 Radius of convergence of e.g.f. is |x| < r where r = LambertW(1) = exp(-LambertW(1)) = 0.56714329040978... %H A205569 Vincenzo Librandi,n,a(n)n=0…200的表%F A20596A(2×n-1)=2(mod 4),a(2×n+2)=0(mod 4),对于n>=1。*EXP(C*N)/((1-C)*(1 +C)^ 2),其中C=LaBrtw(1)=0.5671432904…6月26日,2013,%AE A2055 69E.G.F.:A(x)=1+2×x+6×x ^ 2/2!+ 30×x ^ 3/3!+ 216×x ^ 4/4!+ 1930×x ^ 5/5!+……%%a20596-系数列表[S[ 1(1 +x^ 2 - 2×x*COSH [x]),{x,0, 20 } ],x] *范围[0, 20 ]!(*O-VasLavkToSeVoCeCo,6月26日2013 *)%%O A20555(PARI){A(n)=n!* PoCoFEF(1 /(1 +x^ 2-2*x*COSH(x+x*o(x^ n))),n)} y a2055 69c. A2055 70.0%K A2055 69NANN %O O A2055 690.0,2‰A2055 69A PL D HANAAY,1月28日2012‰内容在OEIS最终用户许可协议下可用:HTTP:/OEIS.Org/许可证