OFFSET
1,4
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..2485
EXAMPLE
The first 4 columns and first 6 rows (excluding t(6,4)) of the table are:
1, 1, 2, 2
1, 3, 4, 6
2, 4, 8, 4
3, 7, 9, 13
4, 6, 10, 8
5, 9, 15
The number of these terms which either divide 6 or are coprime to 4 is 16 (the odd integers, the 2's and the 6's). So t(6,4) = 16.
MATHEMATICA
t[1, 1] = 1; t[m_, n_] := t[m, n] = Block[{c = 0}, Do[ Do[ If[k == m && j == n, Continue[]]; If[Mod[m, t[k, j]] == 0 || GCD[t[k, j], n] == 1, c++ ]; , {j, n}]; , {k, m}]; c]; Flatten[Table[t[d + 1 - i, i], {d, 13}, {i, d}]] (* Ray Chandler, Nov 11 2006 *)
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Leroy Quet, Nov 04 2006
EXTENSIONS
Extended by Ray Chandler, Nov 11 2006
STATUS
approved