the felicitous cluster of years

Prior to now, I hadn't looked at the canonical grouping of my years in anything but in septads; had always thought of it in that Biblical/pseudo-cellular sets of sevens, which felt natural, even organic. [ in progress... ] pentad hexad heptad octad ennead 1965 Row 1, Cell 2 Row 1, Cell 3 Row 1, Cell 4 Row 1, Cell 5 1970 Row 2, Cell 2 Row 2, Cell 3 Row 2, Cell 4 Row 2, Cell 5 1975 Row 3, Cell 2 Row 3, Cell 3 Row 3, Cell 4 Row 3, Cell 5 1980 Row 4, Cell 2 Row 4, Cell 3 Row 4, Cell 4 Row 4, Cell 5 1985 Row 5, Cell 2 Row 5, Cell 3 Row 5, Cell 4 Row 5, Cell 5 1990 Row 6, Cell 2 Row 6, Cell 3 Row 6, Cell 4 Row 6, Cell 5 1995 Row 7, Cell 2 Row 7, Cell 3 Row 7, Cell 4 Row 7, Cell 5 2000 Row 8, Cell 2 Row 8, Cell 3 Row 8, Cell 4 Row 8, Cell 5 2005 Row 9, Cell 2 Row 9, Cell 3 Row 9, Cell 4 Row 9, Cell 5 2010 Row 10, Cell 2 Row 10, Cell 3 Row 10, Cell 4 Row 10, Cell 5 2015 Row 11, Cell 2 Row 11, Cell 3 Row 11, Cell 4 Row 11, Cell 5 2020 Row 12, Cell 2 Row 12, Cell 3 Row 12, Cell 4 Row 12, Cell 5…