OFFSET
1,2
COMMENTS
FORMULA
Column 1: T(n,1) = phi(n). Column 2: T(2*n-1,2) = 0; T(2*n,2) = phi(2*n+1)/2. Column 3: T(3*n-1) = phi(3*n)/2 - 1. Column 4: T(2*n-1,4) = 0; T(2*n,4) = phi(2*n+1)/2 - 1.
EXAMPLE
Triangle begins:
1;
2, 1;
2, 0, 1;
4, 2, 2, 1;
2, 0, 0, 0, 1;
6, 3, 3, 2, 2, 1;
4, 0, 2, 0, 2, 0, 1;
6, 3, 2, 2, 3, 0, 2, 1;
4, 0, 3, 0, 1, 0, 2, 0, 1;
10, 5, 6, 4, 5, 2, 4, 2, 2, 1;
4, 0, 1, 0, 3, 0, 2, 0, 0, 0, 1;
12, 6, 7, 5, 7, 3, 6, 3, 3, 2, 2, 1;
6, 0, 3, 0, 3, 0, 2, 0, 2, 0, 2, 0, 1;
8, 4, 3, 3, 4, 0, 4, 2, 1, 0, 3, 0, 2, 1; ...
where column 1 forms Euler totient function phi(n).
PROG
(PARI) {T(n, k)=local(M=matrix(n, n, r, c, if(r>=c, if(gcd(r-c+1, c)==1, 1, 0)))^2); M[n, k]}
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Leroy Quet, Paul D. Hanna, Apr 16 2006
STATUS
approved