FREE ENERGY BY SIZE OF LOOP
misc. loop functions
 > internal, bulge or hairpin loops > 30: dS(T)=dS(30)+param*ln(n/30)
 1.079
asymmetric internal loops: the ninio equation
 > the maximum correction
 3.0
 > the f(m) array (see ninio for details)
 .4  .3  .2  .1
multibranched loops
  > offset,  free base penalty,  helix penalty
     4.6          .4                 .1