\[\boxed{\text{613\ (613).\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[(2n + 1)^{2} + \left( 2n^{2} + 2n \right)^{2} =\]
\[= \left( 2n^{2} + 2n + 1 \right)^{2}\]
\[4n^{2} + 4n + 1 + 4n^{4} + 8n^{3} + 4n^{2} =\]
\[= 4n^{4} + 4n^{2} + 1 + 8n^{3} + 4n^{2} + 4n\]
\[4n^{4} + 8n^{3} + 8n^{2} + 4n + 1 =\]
\[= 4n^{4} + 8n³ + 8n² + 4n + 1\]