The OEIS is supported by the many generous donors to the OEIS Foundation.
%I #9 Mar 18 2023 03:24:07
%S 1,5,25,35,625,175,15625,385,1225,4375,9765625,1925,244140625,109375,
%T 30625,5005,152587890625,13475,3814697265625,48125,765625,68359375,
%U 2384185791015625,25025,1500625,1708984375,148225,1203125,37252902984619140625,336875,931322574615478515625
%N a(n) is the smallest 5-rough number with exactly n divisors.
%e a(1) = 1 (which is the only number with exactly 1 divisor).
%e a(2) = 5 (since 5 is the smallest prime that is 5-rough).
%e a(3) = 25 (since 5 is the smallest number that is the square of a 5-rough prime).
%e a(4) = 35 (since a number with 4 divisors must be either the cube of a prime or the product of two distinct primes, and the smallest 5-rough numbers of these two types are 5^3 = 125 and 5*7 = 35, respectively, and 35 is the smaller of the two).
%Y Cf. A000005, A005179, A007310, A038547.
%K nonn
%O 1,2
%A _Jon E. Schoenfield_, Mar 18 2023