It is known that if there are base sequences of lengths \(m+1\), \(m+1\), \(m\), \(m\) and \(y\) is a Yang number, then there are \(T\)-sequences of lengths \(y(2m + 1)\). Base sequences of lengths \(m+1\), \(m+1\), \(m\), \(m\) form \(26\), \(27\), \(28\) and some new decompositions into squares are constructed. \(T\)-sequences of lengths \(61(2m + 1)\) for some new decompositions into squares are also presented.