A354192 - OEIS

%I #14 May 20 2022 23:04:48

%S 1,2,4,8,15,16,30,32,60,64,91,120,128,182,187,225,240,256,364,374,450,

%T 480,512,551,728,748,851,900,960,1024,1102,1271,1365,1456,1496,1702,

%U 1800,1920,2048,2204,2279,2542,2730,2805,2867,2912,2992,3375,3404,3600,3840,4096,4307,4408,4558,5084,5460,5610,5734,5824,5963

%N Fixed points of permutation A267099.

%C If k is included, then also 2*k is present. All terms of A048630, i.e., semiprimes p*q where q = A267099(p) are present, as well as their powers, and any products of their combinations.

%e As A267099(3) = 5 and A267099(5) = 3, 15 = 3*5 is present, as well as any 15^k and 2^k * 15, for k >= 0.

%e As A267099(7) = 13 and A267099(13) = 7, 91 = 7*13 is present, and also 91*15 = 1365 is present.

%o (PARI) isA354192(n) = A354193(n);

%Y Subsequence of A072202 and of A354189.

%Y Primitive elements are {2} U A048630.

%Y Cf. A354193 (characteristic function), A000079 (subsequence), A267099.

%K nonn

%O 1,2

%A _Antti Karttunen_, May 19 2022