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A068507
Highly composite numbers sandwiched between twin primes.
11
4, 6, 12, 60, 180, 240, 7560, 55440, 110880, 73329656400, 18632716502400, 130429015516800, 48519593772249600, 149602080797769600, 74377068101903920953600, 927967188666725711881005276648000, 241271469053348685089061371928480000
OFFSET
1,1
COMMENTS
Intersection of (A072826 - 1) and (A072828 + 1). - Lekraj Beedassy, Nov 27 2003
The next term, a(18), is A002182(1002), it has 77 digits. - M. F. Hasler, Jun 23 2019
a(22) > 10^17030, if it exists. - Amiram Eldar, Dec 03 2020
LINKS
M. F. Hasler and Amiram Eldar, Table of n, a(n) for n = 1..21 (terms 1..20 from M. F. Hasler)
Brian Hayes, Does having prime neighbors make you more composite?, Bit-Player Article, Nov 04 2021
FORMULA
a(n) = A002182(A321995(n)). - Amiram Eldar, Dec 03 2020
EXAMPLE
60 is between 59 and 61.
CROSSREFS
This is also the intersection of A002182 and A014574.
Sequence in context: A154666 A050537 A114413 * A133454 A061072 A130435
KEYWORD
nonn
AUTHOR
Lekraj Beedassy, Mar 25 2002
EXTENSIONS
Corrected and extended by Lior Manor Jun 03 2002
More terms from Bill McEachen, May 24 2006
a(18)-a(20) from M. F. Hasler, Jun 23 2019
STATUS
approved