I've done a little research and maths about a adequate formula for corn. This is based on NPK-content on plant residue analyses. I've then transfered these data into a "modern concept" of
nutrient composition:
Formula without guarantee or if you prefer: WITHOUT COVENANT AGAINST GRANTOR'S STATEMENT
Explanations: Grains contain much more nitrogen than forage and other parts, that is why I suggest higher N-content in the fruiting formula. 2. Forage and cobs have very high K-content, that's why K-content should be high in the formula. General growth-rate of corn is rather high, - and that's why a rather high feeding (yet not a aggressive) strategy should be appropriate. But again: this formula still reflects my general tendency for economic formulas, that do not stress plants into excessive growth, but rather simulate a natural environment. Both formulas have relatively high Phosphorus and Calcium content (50 ppm of P and 140 ppm of Ca would be sufficient), this to assure enough P- and Ca content in case the formula is used in notably lower concentrations.
PS: I've also added a comparative formula for tomatoes, that illustrates and helps understanding the process of getting to a nutrient formula - based on a plant analyses.