OFFSET
1,2
COMMENTS
EXAMPLE
Northwest corner:
1...3...7...13...21...31
2...4...8...14...22...32
5...9...15..23...33...45
6...10..16..24...34...46
11..17..25..35...47...61
MATHEMATICA
z = 40;
c[k_] := k^2 - k + 1
c = Table[c[k], {k, 1, z}] (* A002061 *)
f[n_] := If[MemberQ[c, n], 1, 1 + f[n - 1]]
f = Table[f[n], {n, 1, 800}] (* A074294 *)
r[n_] := Flatten[Position[f, n]]
t[n_, k_] := r[n][[k]]
TableForm[Table[t[n, k], {n, 1, 8}, {k, 1, 7}]]
p = Flatten[Table[t[k, n - k + 1], {n, 1, 16}, {k, 1, n}]] (* A194011 *)
q[n_] := Position[p, n]; Flatten[Table[q[n], {n, 1, 80}]] (* A194012 *)
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Clark Kimberling, Aug 15 2011
STATUS
approved