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A295644 Rectangular array, by antidiagonals; row 1 is the ordered list of all k having at most 2 unitary divisors; for n > 1, row n is the ordered list of all k having 2^n unitary divisors.

%I A295644 #20 Jan 03 2023 23:11:03
%S A295644 1,2,6,3,10,30,4,12,42,210,5,14,60,330,2310,7,15,66,390,2730,30030,8,
%T A295644 18,70,420,3570,39270,510510,9,20,78,462,3990,43890,570570
%N A295644 Rectangular array, by antidiagonals; row 1 is the ordered list of all k having at most 2 unitary divisors; for n > 1, row n is the ordered list of all k having 2^n unitary divisors.
%C A295644 Every positive integer occurs exactly once, so that as a sequence, this is a permutation of the positive integers.
%C A295644 row 1: A000961
%C A295644 row 2: A007774
%C A295644 row 3: A033992
%C A295644 row 4: A033993
%C A295644 col 1: A231209
%e A295644 Northwest corner:
%e A295644      1    2    3    4    5    7    8    9   11
%e A295644      6   10   12   14   15   18   20   21   22
%e A295644     30   42   60   66   70   78   84   90  102
%e A295644    210  330  390  420  462  510  546  570  630
%e A295644   2310 2730 3570 3990 4290 4620 4830 5460 5610
%t A295644 z = 10000;
%t A295644 t = Table[2^PrimeNu[n], {n, 1, z}] ;(*  A035555 *)
%t A295644 r[n_] := Flatten[Position[t, 2^n]]; r[1] = Join[{1}, r[1]];
%t A295644 v[n_, k_] := r[n][[k]];
%t A295644 TableForm[Table[v[n, k], {n, 1, 5}, {k, 1, 15}]]  (* A295644 array *)
%t A295644 Table[v[n - k + 1, k], {n, 5}, {k, n, 1, -1}] // Flatten  (* A295644 sequence *)
%Y A295644 Cf. A034444.
%Y A295644 As an array, essentially the same as A125666.
%K A295644 nonn,tabl,more
%O A295644 1,2
%A A295644 _Clark Kimberling_, Jun 26 2018