A046438 8 steps needed to reach a prime under 'Sum of digits raised to its digits powers' procedure.

55, 155, 226, 244, 247, 255, 262, 274, 424, 427, 442, 472, 505, 515, 525, 550, 551, 552, 622, 724, 742, 1039, 1093, 1139, 1193, 1234, 1238, 1243, 1283, 1309, 1319, 1324, 1328, 1342, 1382, 1390, 1391, 1423, 1432, 1823, 1832, 1903, 1913, 1930, 1931