Question

write a number which represent triangle as well square pattern​

Answer 1

Answer:

Its solutions are (xn,zn) where zn+2√2xn=(3+2√2)n. So x1=1, z1=3 giving 1 as square-triangular. Then x2=6, z2=17 giving 36 as square-triangular. Then x3=35, z3=99 giving 1225 as square-triangular, etc.