OFFSET
1,2
COMMENTS
EXAMPLE
Northwest corner:
1...2...4...6...9...12
3...5...7...10..13..17
8...11..14..18..22..27
15..19..23..28..33..39
24..29..34..40..46..53
MATHEMATICA
z = 50;
c[k_] := Floor[((k + 1)^2)/4];
c = Table[c[k], {k, 1, z}] (* A002620 *)
f[n_] := If[MemberQ[c, n], 1, 1 + f[n - 1]]
f = Table[f[n], {n, 1, 400}] (* [A122197] *)
r[n_] := Flatten[Position[f, n]]
t[n_, k_] := r[n][[k]]
TableForm[Table[t[n, k], {n, 1, 7}, {k, 1, 7}]]
p = Flatten[
Table[t[k, n - k + 1], {n, 1, 11}, {k, 1, n}]] (* A194061 *)
q[n_] := Position[p, n]; Flatten[
Table[q[n], {n, 1, 90}]] (* A194062 *)
KEYWORD
nonn,tabl
AUTHOR
Clark Kimberling, Aug 14 2011
STATUS
approved