Eighteen
Had an interesting dream last night regarding the number 18, probably thanks to the trataka meditation over the Sigillum Dei. This is what I found out about number 18: The Hebrew word for life (chai) has a numeric value of 18 Shemoneh Esrei is a type of prayer (the name means eighteen) 18 is a heptagonal number. Heptagonal numbers are numbers that are constructed by combining heptagons with ascending sizes. Regarding the heptagonal number, if we take the following formula: if we replace n with the number 3, we will get (5 *3^2 - 3*3)/2 , which is 18. Which means 18 is the third heptagonal number. A bit more interesting when we consider that Sigillum Dei commonly contains 3 heptagons. Anyway, I need to delve deeper into the Shemoneh Esrei, I checked the first part of the prayer so far and it does seem interesting.