|
%I #12 Nov 01 2019 10:28:06
%S 2,9,27,81,243,704,1664,3840,8704,19456,43008,94208,204800,442368,
%T 950272,2031616,4325376,9175040,19398656,40894464,85983232,180355072,
%U 377487360,788529152,1644167168,3422552064,7113539584,14763950080
%N a(n) = n-th integer from among those positive integers with an exponent of n in their prime-factorizations.
%e The positive integers with an exponent 6 in their prime-factorizations are 64 = 2^6, 192 = 2^6 *3^1, 320 = 2^6 *5^1, 448 = 2^6 *7^1, 576 = 2^6 *3^2, 704 = 2^6 *11^1, 729 = 3^6,...etc. The 6th of these is 704, so a(6) = 704.
%t f[n_] := Min[3^n, 2^n*(2n - 1)];Table[f[n], {n, 30}] (* _Ray Chandler_, Nov 23 2006 *)
%K nonn
%O 1,1
%A _Leroy Quet_, Nov 19 2006
%E Extended by _Ray Chandler_, Nov 23 2006
|
