OFFSET
1,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..1000
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 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Sep 10 2011
STATUS
approved