triangular square number

A square triangualr number is a positive integer that is simultaneously square and triangular. Let T_n denote the nth triangular number and S_m the mth square number, then a number which is both triangular and square satisfies the equation T_n = S_m, or 1/2 n(n + 1) = m^2.

cubic triangular number | Nicomachus's theorem | pentagonal square number | pentagonal square triangular number | square number | square root | triangular number