In June of 2016, I posted about Golden Semiprimes. Today I was reminded of this class of numbers once again because today's number, 24709, is a prime that forms the greater prime in a series of semiprimes that give increasingly better approximations to the golden ratio. This OEIS series is A165570: successively better golden semiprimes and begins:
6, 15, 77, 589, 851, 1363, 15229, 201563, 512893, 644251, 1366553, 3416003, 7881197, 377331139, 400711231, 2963563859, 4035221017, 28862500577, 52027213697, 133793658289, 418298061641, 1363588753103, 1970239102459The OEIS series that gives the greater primes in these semiprimes is A165572: greater prime factor of Successively Better Golden Semiprimes. The series begins:
3, 5, 11, 31, 37, 47, 157, 571, 911, 1021, 1487, 2351, 3571, 24709, 25463, 69247, 80803, 216103, 290141, 465277, 822691, 1485373, 1785473For today's number 24709, the associated semiprime is 377331139 and the factorisation is 15271×24709. In a little over two years time, the next prime in series A165572 will pop up, namely 25463.
No comments:
Post a Comment