If 112+122+132+...∞=π26, then 112+132+152+.... equals
π28
π212
π23
π22
112+132+152+172+...
=(112+122+132+142+152+162+172+...)−(122+142+162+...)
=π26−14(112+122+132+...)
=π66−14(π26)
=π28