panthrMath/basicFunc/gratio.js
function f(x, n) {
         return Math.exp((logpg + x - Math.log(series(snTerm(x), n + 1))) / a);
      }
function f(x, n) {
         return Math.exp((logpg + x - Math.log(series(snTerm(x), n + 1))) / a);
      }
function f ( x , n ) { return Math . exp ( ( logpg + x - Math . log ( series ( snTerm ( x ) , n + 1 ) ) ) / a ) ; }
See formula 34, where `n` is off by 1
See formula 34 where n is off by 1