Dear all, I had an issue when calculating the triangular number with the formula <.@:-:@:(* >:) in list context. Starting from 5928745 the outcome in list context is larger than the correct value (additionally calculated with the binomial coefficient in the first box):
t=: <.@:-:@:(* >:) ((2&!)@:>:; t ;{.@:t@:,~) 5928744 +--------------+--------------+--------------+ |17575005673140|17575005673140|17575005673140| +--------------+--------------+--------------+ ((2&!)@:>:; t ;{.@:t@:,~) 5928745 +--------------+--------------+--------------+ |17575011601885|17575011601885|17575011601886| +--------------+--------------+--------------+ JVERSION Engine: j902/j64avx2/windows Release-a: commercial/2020-12-05T13:36:01 Library: 9.02.08 Platform: Win 64 Installer: J902 install InstallPath: c:/users/wzhbsn/_/opt/j Contact: www.jsoftware.com Thanks. Stefan. ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm