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Prime powers (p^k, k >= 2) in A090252 in order of appearance.
3

%I #12 Jun 19 2022 02:20:54

%S 4,9,8,25,16,27,49,121,32,169,125,289,81,361,529,64,841,343,961,128,

%T 1369,1681,1849,2209,243,2809,3721,4489,5041,5329,1331,6241,6889,3481,

%U 256,10609,11449,11881,625,12769,7921,9409,10201,2197,26569,32041,32761,16129

%N Prime powers (p^k, k >= 2) in A090252 in order of appearance.

%H Michael De Vlieger, <a href="/A355012/b355012.txt">Table of n, a(n) for n = 1..1009</a>

%H Michael De Vlieger, <a href="/A355012/a355012.png">Annotated log-log scatterplot of A090252(n)</a>, n = 1..2^12, labeling primes in red, squarefree semiprimes in green, highlighting composite prime powers in gold and labeling them in boldface.

%t Select[Import["https://oeis.org/A090252/b090252.txt", "Data"][[1 ;; 4000, -1]], CompositeQ[#] && PrimePowerQ[#] &]

%Y Cf. A090252, A246547, A354165, A355013, A355014.

%K nonn

%O 1,1

%A _Michael De Vlieger_, Jun 15 2022