This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A273290 #16 Jun 03 2016 15:00:54
%S A273290 2,3,4,5,4,7,8,9,9,11,8,13,9,9,16,17,27,19,8,25,25,23,16,25,49,27,8,
%T A273290 29,27,31,32,49,49,25,16,37,49,49,16,41,27,43,8,27,121,47,32,49,125,
%U A273290 49,8,53,81,49,16,121,169,59,16,61,169,27,64,49,27,67,8,169,125
%N A273290 A273288(n)^Omega(n), where Omega = A001222.
%C A273290 a(n) is by definition the power of a prime. It coincides with n iff n is the power of a prime (A246655).
%C A273290 a(n) <= A273291(n)
%H A273290 Giuseppe Coppoletta, <a href="/A273290/b273290.txt">Table of n, a(n) for n = 2..10000</a>
%F A273290 a(n) = A273288(n)^A001222(n).
%e A273290 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.
%e A273290 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.
%t A273290 Table[Prime[PrimePi@ Median@ #]^Length@ # &@ Flatten@ Apply[Table[#1 {#2}] &, FactorInteger@ n, 1], {n, 2, 75}] (* _Michael De Vlieger_, May 27 2016 *)
%o A273290 (Sage) def pfwr(n): return flatten([([p] * m) for (p, m) in factor(n)]) # (list of prime factors of n with repetition)
%o A273290 [previous_prime(floor(median(pfwr(n)))+1)^sloane.A001222(n) for n in (2..70)]
%Y A273290 Cf. A273284, A273288, A273291, A079867, A246655, A001222.
%K A273290 nonn
%O A273290 2,1
%A A273290 _Giuseppe Coppoletta_, May 25 2016