5. Gol><>, A001489
// n=>40-n// //[>[-]<[>+<-],]>>+<[->[>>+<<-]>[<+>-]>[<+>-]<<<]>>>>++++++[<++++++++>-]<<[>+<-]>+. //ip@ // ;/**/ //I01-* h // ;/**/ Use single-line comment markers in C# to redirect the Fish IP to the operative code, I01-*h, reading input, multiplying by -1, and outputting the result. Gol><> made reading input and dumping the stack as a number easy compared to raw ><>.
Spaces inserted to insure the proper flow of the Fish and Runic IPs, where both C# and Jelly ignore the leading whitespace on the last line (and is a NOP cell in both fungoids).