A195185 - OEIS

%I #9 Nov 06 2017 04:32:43

%S 1,2,3,4,5,6,10,7,8,9,14,11,12,13,15,21,19,16,17,18,20,27,25,22,23,24,

%T 26,28,36,34,32,29,30,31,33,35,45,44,42,40,37,38,39,41,43,55,54,53,51,

%U 49,46,47,48,50,52,65,64,63,61,59,56,57,58,60,62,66,78,76,75

%N Inverse permutation of A195184; every positive integer occurs exactly once.

%H G. C. Greubel, <a href="/A195185/b195185.txt">Table of n, a(n) for n = 1..1000</a>

%t p[n_] := If[PrimeQ[n], n, 1]

%t Table[p[n], {n, 1, 90}]  (* A089026 *)

%t g[1] = {1}; g[n_] := Insert[g[n - 1], n, p[n]]

%t f[1] = g[1]; f[n_] := Join[f[n - 1], g[n]]

%t f[20] (* A195183 *)

%t row[n_] := Position[f[30], n];

%t u = TableForm[Table[row[n], {n, 1, 5}]]

%t v[n_, k_] := Part[row[n], k];

%t w = Flatten[Table[v[k, n - k + 1], {n, 1, 13},

%t   {k, 1, n}]]  (* A195184 *)

%t q[n_] := Position[w, n]; Flatten[

%t Table[q[n], {n, 1, 80}]]  (* A195185 *)

%Y Cf. A195183, A195184, A089026, A194959.

%K nonn

%O 1,2

%A _Clark Kimberling_, Sep 10 2011