Friday the 13th on 17bii Solver

[rprosperi]

(01-13-2017 07:37 PM)Don Shepherd Wrote:  It occurred to me that this would be an excellent equation for the 17bii solver, making use of its included functions like sigma, IDIV, MOD, and of course L() and G().

\(\Sigma\)(M:1:12:1:0xL(A:IDIV(14-M:12))xL(Y:YEAR-G(A))xL(MM:M+12xA-2)+IF(MOD(DOM+G(Y)+IDIV(G(Y):4)-IDIV(G(Y):100)+IDIV(G(Y):400)+IDIV(31xG(MM):12):7)=DAY:1:0))-ANS

Thanks Don, it seems it even works in the 17BII+ Silver Edition... (confirmed for 2015(3), 2016(1) and 2017(2) ).