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 A363192 #9 May 21 2023 12:56:13
%S A363192 1,25,2187,703125,93096125,10229709861,197584409639,32044275110699,
%T A363192 164029657560618375
%N A363192 a(n) is the least start of a run of exactly n consecutive powerful numbers (A001694) that are odd, or -1 if no such run exists.
%C A363192 No more terms below 10^18.
%C A363192 At most one of the n odd consecutive powerful numbers in the run is a perfect square. - _David A. Corneth_, May 21 2023
%e A363192 a(1) = 1, since 1 is an odd powerful number, followed by an even powerful number, 4 = 2^2.
%e A363192 a(2) = 25, since 25 = 5^2 and 27 = 3^3 are two consecutive odd powerful numbers, preceded by an even powerful number, 16 = 2^4, and followed by an even powerful number, 32 = 2^5.
%t A363192 seq[lim_] := Module[{pow = Union[Flatten[Table[i^2*j^3, {j, 1, lim^(1/3)}, {i, 1, Sqrt[lim/j^3]}]]], s = {}, rem, ind}, rem = Join[{0}, Mod[pow, 2]]; Do[ind = SequencePosition[rem, Join[{0}, Table[1, {k}], {0}], 1]; If[ind == {}, Break[]]; AppendTo[s, pow[[ind[[1, 1]]]]], {k, 1, Infinity}]; s]; seq[1.1*10^10]
%Y A363192 Cf. A001694, A062739, A349062, A363189, A363190, A363191.
%K A363192 nonn,more
%O A363192 1,2
%A A363192 _Amiram Eldar_, May 21 2023