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