The sequence of numbers $1$, $3$, $6$, $10$, $15$, $21$, $28$, $36$, … with general term $T(n)=1+2+\ldots+n$ is called the sequence of triangle numbers.
Resources for HKDSE Mathematics
Resources for HKDSE Mathematics
The sequence of numbers $1$, $3$, $6$, $10$, $15$, $21$, $28$, $36$, … with general term $T(n)=1+2+\ldots+n$ is called the sequence of triangle numbers.
