OFFSET
0,4
LINKS
Indranil Ghosh and Chai Wah Wu, Table of n, a(n) for n = 0..3000 (terms for n = 0..100 from Indranil Ghosh)
PROG
(Python)
def a(n):
s=0
for a in range(0, n+1):
for b in range(0, n+1):
for c in range(0, n+1):
for d in range(0, n+1):
if (a!=b and a!=d and b!=d and c!=a and c!=b and c!=d):
if a*d-b*c==n:
s+=1
return s
print([a(n) for n in range(0, 52)]) # Indranil Ghosh, Nov 20 2016
CROSSREFS
KEYWORD
nonn
AUTHOR
Indranil Ghosh, Nov 20 2016
STATUS
approved