src/index.js
function U(l,m,n,R_1,R_lm1) {
    
    return P(0,l,m,n,R_1,R_lm1);
}
function U(l,m,n,R_1,R_lm1) {
    
    return P(0,l,m,n,R_1,R_lm1);
}
functions to compute terms U, V, W of Eq.8.1 (Table II)