OFFSET
1,2
COMMENTS
a(n) is the LCM of the terms in the n-th antidiagonal of the A126572 array. - Michel Marcus, Mar 14 2018
EXAMPLE
The integers coprime to 4 are 1,3,5,... The first of these is 1. The integers coprime to 3 are 1,2,4,5,... The 2nd of these is 2. The integers coprime to 2 are 1,3,5,7,9,... The 3rd of these is 5. And the integers coprime to 1 are 1,2,3,4,5,... The 4th of these is 4. So a(5) = lcm(1,2,5,4) = 20.
PROG
(PARI) cop(k, j) = {my(nbc = 0, i = 0); while (nbc != j, i++; if (gcd(i, k)==1, nbc++)); i; }
a(n) = lcm(vector(n, k, cop(k, n-k+1))); \\ Michel Marcus, Mar 14 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
Leroy Quet, Aug 20 2007
EXTENSIONS
More terms from Sean A. Irvine, Nov 25 2010
STATUS
approved