OFFSET
2,1
COMMENTS
LINKS
Giuseppe Coppoletta, Table of n, a(n) for n = 2..10000
EXAMPLE
a(70) = A273291(70) = 5^3 because the median of its prime factors [2, 5, 7] is the central value 5 (prime) and Omega(70)=3.
a(308) = 3^4 because Omega(308)=4 and the median of [2, 2, 7, 11] is (2+7)/2 = 4.5, whose previous prime is 3.
MATHEMATICA
Table[Prime[PrimePi@ Median@ #]^Length@ # &@ Flatten@ Apply[Table[#1 {#2}] &, FactorInteger@ n, 1], {n, 2, 75}] (* Michael De Vlieger, May 27 2016 *)
PROG
(Sage) def pfwr(n): return flatten([([p] * m) for (p, m) in factor(n)]) # (list of prime factors of n with repetition)
[previous_prime(floor(median(pfwr(n)))+1)^sloane.A001222(n) for n in (2..70)]
CROSSREFS
KEYWORD
nonn
AUTHOR
Giuseppe Coppoletta, May 25 2016
STATUS
approved