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A066617
Composites of form prime+1 containing a record number of prime factors.
1
4, 8, 24, 32, 128, 384, 1152, 3584, 5120, 6144, 8192, 73728, 131072, 524288, 5505024, 10616832, 14680064, 18874368, 109051904, 169869312, 654311424, 738197504, 2147483648, 21474836480, 51539607552, 824633720832, 3710851743744
OFFSET
1,1
COMMENTS
The sequence contains all numbers of the form (Mersenne Prime)+1 as a subset. - Hugo Pfoertner, Sep 10 2004
EXAMPLE
a(19)=109051904=13*2^23: 24 prime factors, a(20)=169869312=3^4*2^21: 25 prime factors, a(21)=654311424=13*3*2^24: 26 prime factors. a(19)-1, a(20)-1 and a(21)-1 are primes.
PROG
(PARI) {A066617(a, b) = local(p, c, d); forprime(p=a, b, d=bigomega(p+1); if(d>c, c=d; print1(p+1, ", ")))} A066617(3, 10^7)
CROSSREFS
Cf. Mersenne Primes + 1: A072868(n)=A000668(n)+1.
Sequence in context: A291548 A212019 A075708 * A272272 A024589 A062015
KEYWORD
nonn
AUTHOR
G. L. Honaker, Jr., Jan 13 2002
EXTENSIONS
More terms from Jason Earls, Jan 15 2002
More terms from Hugo Pfoertner, Sep 10 2004
a(24)-a(27) from Donovan Johnson, Dec 08 2009
STATUS
approved