A195185 Inverse permutation of A195184; every positive integer occurs exactly once.

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, 26, 28, 36, 34, 32, 29, 30, 31, 33, 35, 45, 44, 42, 40, 37, 38, 39, 41, 43, 55, 54, 53, 51, 49, 46, 47, 48, 50, 52, 65, 64, 63, 61, 59, 56, 57, 58, 60, 62, 66, 78, 76, 75

Offset: 1

Author

Clark Kimberling, Sep 10 2011

Keywords

• nonn

Links

• G. C. Greubel, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A195183, A195184, A089026, A194959.

Programs

Mathematica

p[n_] := If[PrimeQ[n], n, 1]
Table[p[n], {n, 1, 90}]  (* A089026 *)
g[1] = {1}; g[n_] := Insert[g[n - 1], n, p[n]]
f[1] = g[1]; f[n_] := Join[f[n - 1], g[n]]
f[20] (* A195183 *)
row[n_] := Position[f[30], n];
u = TableForm[Table[row[n], {n, 1, 5}]]
v[n_, k_] := Part[row[n], k];
w = Flatten[Table[v[k, n - k + 1], {n, 1, 13},
  {k, 1, n}]]  (* A195184 *)
q[n_] := Position[w, n]; Flatten[
Table[q[n], {n, 1, 80}]]  (* A195185 *)