1, 1-t, 2*t^2 - 3*t + 1, -6*t^3 + 11*t^2 - 6*t + 1
Formula: prod(1 - k*t for k in range(1,n))
Actions: s[1], (-t+1)*s[2], (t^2-t)*s[2, 1] + (-t+1)*s[3], (-t^3+t^2)*s[2, 1, 1] + (t^2-t)*s[2, 2] + (-t^3+2*t^2-t)*s[3, 1] + (-t+1)*s[4], (t^4-t^3)*s[2, 1, 1, 1] + (t^4-2*t^3+t^2)*s[2, 2, 1] + (t^4-3*t^3+2*t^2)*s[3, 1, 1] + (t^4-2*t^3+2*t^2-t)*s[3, 2] + (t^4-2*t^3+2*t^2-t)*s[4, 1] + (-t+1)*s[5], (-t^5+t^4)*s[2, 1, 1, 1, 1] + (-t^5+3*t^4-2*t^3)*s[2, 2, 1, 1] + (-t^5+2*t^4-t^3)*s[2, 2, 2] + (-2*t^5+4*t^4-2*t^3)*s[3, 1, 1, 1] + (-3*t^5+6*t^4-5*t^3+2*t^2)*s[3, 2, 1] + (2*t^4-3*t^3+t^2)*s[3, 3] + (-t^5+4*t^4-5*t^3+2*t^2)*s[4, 1, 1] + (-2*t^5+4*t^4-3*t^3+2*t^2-t)*s[4, 2] + (-t^5+2*t^4-2*t^3+2*t^2-t)*s[5, 1] + (-t+1)*s[6]
Operadia