55. A NEW RESULT CONCERNING A MERSENNE NUMBER.—(Compare N. 23, 33, v. 1, p. 333, 404). On 9 February 1946 I finished testing the character of the Mersenne number M229 = 2229 - 1 = 8627 18293 34882 04734 29344 48278 46281 81556 38862 15212 98319 39531 55279 74911. Since the final residue, the 228th, was not zero the conclusion is that M229 is composite.     The Lucasian sequence used was 4, 14, 194, 37634, 1416317954, etc.     The 228th residue was found to be 1970 11660 94225 75309 56180 91126 86257 27776 96596 41856 06805 84362 68648 91891.     Thus, among these numbers Mp, up to and including p = 257, there are only three whose characters are unknown, namely: p = 193, 199, 227. There are, however, eleven Mp, known to be composite, but of which no factor is known.     I have begun a similiar investigation of M199. HORACE S. UHLER     12 Hawthorne Avenue     Hamden 14, Connecticut