256{| align=right cellpadding=3 id=toc style="margin-left: 15px;"\n|- \n| align="center" colspan=2 | Years:252 253 254 255 - 256 - 257 258 259 260\n|-\n| align="center" colspan=2 | Decades: 220s 230s 240s - 250s - 260s 270s 280s\n|- \n| align="center" | Centuries: 2nd century - 3rd century - 4th century\n|}
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"Each problem that I solved became a rule which served afterwards to solve other problems." - Rene Descartes (1596-1650), "Discours de la Methode" |
