www.mikescher.com/www/statics/euler/Euler_Problem-028.php

<?php

return 
[
	'number'      => 28,
	'date'        => '2014-09-18',
	'title'       => 'Number spiral diagonals',
	'abbreviated' => false,
	'steps'       => 28514,
	'time'        => 15,
	'width'       => 54,
	'height'      => 2,
	'value'       => 669171001,
];