Editing Square triangular number (section)

{{short description|Integer that is both a perfect square and a triangular number}}
{{for|squares of triangular numbers|squared triangular number}}
[[File:square_triangular_number_36.svg|234px|thumb|Square triangular number 36 depicted as a triangular number and as a square number.]]

In [[mathematics]], a '''square triangular number''' (or '''triangular square number''') is a number which is both a [[triangular number]] and a [[square number]]. There are [[Infinity|infinitely many]] square triangular numbers; the first few are:
{{bi|left=1.6|0, 1, 36, {{val|1225}}, {{val|41616}}, {{val|1413721}}, {{val|48024900}}, {{val|1631432881}}, {{val|55420693056}}, {{val|1882672131025}} {{OEIS|id=A001110}}}}