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Least number k that can be written as k^2 * j with 0 < j <= k and gcd(k, j) = 1 in n ways.
1

%I #9 Dec 24 2015 23:07:36

%S 2,1,100,900,44100,108900,1232100,11492100,5336100,12744900,97416900

%N Least number k that can be written as k^2 * j with 0 < j <= k and gcd(k, j) = 1 in n ways.

%t t = Sort[ Flatten[ Table[n = k^2*j; If[ GCD[k, j] == 1 && 10^5 < n < 10^8, n, {}], {k, 15000}, {j, k}]]]; l = Length[t]; t[[Select[ Range[l - 11], t[[ # ]] == t[[ # + 9]] &]]]

%Y Cf. A102354, A104021, A104023.

%K nonn

%O 0,1

%A _Leroy Quet_ and _Robert G. Wilson v_, Feb 23 2005