OFFSET
1,3
COMMENTS
a(n) = (number of pairs (i,j) in [1..n] X [1..n] with integral arithmetic mean) - (number of pairs (i,j) in [1..n] X [1..n] with integral harmonic mean).
LINKS
Alois P. Heinz, Table of n, a(n) for n = 1..10000
PROG
(Python)
def A362936(n): return ((n-1)**2>>1)-(sum(1 for x in range(1, n+1) for y in range(1, x) if not (x*y<<1)%(x+y))<<1) # Chai Wah Wu, Aug 29 2023
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Aug 28 2023
STATUS
approved