OFFSET
1,2
COMMENTS
LINKS
Alois P. Heinz, Rows n = 1..141, flattened
EXAMPLE
The first rows of the triangle are:
1,
2, 4,
3, 6, 7,
4, 8, 12, 14,
5, 10, 15, 20, 13,
6, 12, 14, 24, 30, 28,
7, 14, 21, 28, 35, 42, 19,
8, 16, 24, 26, 40, 48, 56, 42,
9, 18, 19, 36, 45, 38, 63, 72, 37,
MAPLE
with(numtheory):
T:= (n, k)-> add(add(phi(ilcm(c, d)), c=divisors(n)), d=divisors(k)):
seq (seq (T(n, k), k=1..n), n=1..14); # Alois P. Heinz, Sep 12 2012
MATHEMATICA
t[n_, k_] := Sum[ EulerPhi[ LCM[c, d]], {c, Divisors[n]}, {d, Divisors[k]}]; Table[t[n, k], {n, 1, 12}, {k, 1, n}] // Flatten (* Jean-François Alcover, Jul 23 2013 *)
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Peter Luschny, Sep 12 2012
STATUS
approved