Triangle T(n,k) which contains 4*n!*2^floor((n+1)/2) times the coefficient [t^n x^k] exp(t*x)/(3 + exp(2*t)) in row n, column k.

A171683

Triangle T(n,k) which contains 4*n!*2^floor((n+1)/2) times the coefficient [t^n x^k] exp(t*x)/(3 + exp(2*t)) in row n, column k.

Terms

    a(0) =1a(1) =-1a(2) =2a(3) =-1a(4) =-2a(5) =2a(6) =1a(7) =-6a(8) =-6a(9) =4a(10) =10a(11) =4a(12) =-12a(13) =-8a(14) =4a(15) =26a(16) =100a(17) =20a(18) =-40a(19) =-20a(20) =8a(21) =-154a(22) =156a(23) =300a(24) =40a(25) =-60a(26) =-24a(27) =8a(28) =-1646a(29) =-2156

External references