Search: id:A060524 Results 1-1 of 1 results found. %I A060524 %S A060524 1,0,1,1,0,1,0,5,0,1,9,0,14,0,1,0,89,0,30,0,1,225,0,439,0,55,0,1,0, %T A060524 3429,0,1519,0,91,0,1,11025,0,24940,0,4214,0,140,0,1,0,230481,0,122156, %U A060524 0,10038,0,204,0,1,893025,0,2250621,0,463490,0,21378,0,285,0,1,0 %N A060524 Triangle T(n,k) giving number of degree-n permutations with k odd cycles, k=0..n. %C A060524 The row polynomials t(n,x):=sum(T(n,k)*x^k,k=0..n) satisfy the recurrence relation t(n,x)= x*t(n-1,x) + ((n-1)^2)*t(n-2,x); t(-1,x)=0,t(0,x)=1. W. Lang, see above. %C A060524 This is an example of a Sheffer triangle (coefficient triangle for Sheffer polynomials). In the umbral calculus (see the Roman reference given under A048854) s(n,x) := sum(T(n,k)*x^k,k=0..n) would be called Sheffer polynomials for (1/cosh(t),tanh(t)), which translates to the e.g.f. for column nr. k>=0 given by (1/sqrt(1-x^2))*((artanh(x))^k)/k!. The e.g.f. given below is rewritten in this Sheffer context as (1/ sqrt(1-x^2))*exp(y*ln(sqrt((1+x)/(1-x))))= (1/sqrt(1-x^2))*exp(y*artanh(x)). The rows of the Jabotinsky type triangle |A049218| provide the coefficients of the associated polynomials. W. Lang (wolfdieter.lang_AT_physik_DOT_uni-karlsruhe_DOT_de), Feb 24 2005. %C A060524 The solution of the differential-difference relation f(n+1,x)= diff(f(n, x),x) + (n^2)*f(n-1,x), n>=1, with inputs f(0,x) and f(1,x)=diff(f(0, x),x) is f(n,x)= t(n,d_x)*f(0,x), with the differential operator d_x:=d/dx and the row polynomials t(n,x) defined above. This problem appears in a computation of thermo field dynamics where f(0,x)=1/ cosh(x). See the triangle A060081. W. Lang, see above. %C A060524 The inverse of the Sheffer matrix T with elements T(n,k) is the Sheffer matrix A060081. - W. Lang, Jul 22 2005 %C A060524 T(n,k)=0 if n-k= 1(mod 2), else T(n,k)= sum of M2(n,p), p from {1,..., A000041(n)} restricted to partitions with exactly k odd parts and any nonnegative number of even parts. For the M2-multinomial numbers in A-St order see A036039(n,p). W. Lang, Aug 07 2007. %F A060524 E.g.f.: (1+x)^((y-1)/2)/(1-x)^((y+1)/2). %F A060524 T(n, k) = T(n-1, k-1) + ((n-1)^2)*T(n-2, k); T(-1, k):=0, T(n, -1):=0, T(0, 0)=1, T(n, k)=0 if n