SPSSs Order 55;

In 1947 Chris Bouwkamp found the first SPSS of order 55 : 16176A CJB 1947

In 1967 P.J. Federico found the second SPSS of order 55 : 16303A PJF 1967

In 1999 Ian Gambini published 2 small SPSS of order 55 : 939A I_G 1999, 55 : 1120A I_G 1999

In 2014 Brian Trial found 5188 order 55 SPSSs.

In 2018 Bernard Moss found 931 order 55 SPSSs using a transform applied to Brian Trial's discoveries.

More recently, in 2020 Bernard Moss found a number of quite small SPSSs in order 55, including the smallest known of this order 55 : 740 BLM.

There are 6983 known SPSSs of Order 55. Files provided as;