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A348839
Composite numbers all of whose prime factors are Mersenne primes.
0
9, 21, 27, 49, 63, 81, 93, 147, 189, 217, 243, 279, 343, 381, 441, 567, 651, 729, 837, 889, 961, 1029, 1143, 1323, 1519, 1701, 1953, 2187, 2401, 2511, 2667, 2883, 3087, 3429, 3937, 3969, 4557, 5103, 5859, 6223, 6561, 6727, 7203, 7533, 8001, 8649, 9261
OFFSET
1,1
EXAMPLE
9=3*3, 21=3*7, 27=3^3, 49=7*7, 63=3*31. 3,7,31,... are the first Mersenne primes.
CROSSREFS
Composite terms in A056652.
Cf. A000668.
Sequence in context: A128462 A186815 A106214 * A036316 A340122 A339728
KEYWORD
nonn
AUTHOR
Marc Morgenegg, Nov 01 2021
STATUS
approved