Check whether the input matrix is a figurate number triangle: http://mathworld.wolfram.com/FigurateNumberTriangle.html
you should probably add a test case where the correct answer is false.
True!
I added a few more tests as suggested.
606 Solvers
Make one big string out of two smaller strings
1016 Solvers
Vectorize the digits of an Integer
228 Solvers
335 Solvers
183 Solvers