SQUARE TRIANGULAR NUMBER

1,3,6,10,15,21,28,36,...n(n+1)/2  are triangular number and in this list 1 and 36 are also perfect square number. Here 1, 36 are squared triangular number.
1, 36 , 1225, 41616, 1413721, 48024900, 1631432881, 55420693056 .
ARYABHATTA contributed methods of finding square root and cube root of a number in his book Ganitpada.