OFFSET
1,2
COMMENTS
Numbers m such that for some v, there are exactly m ways to write v = i^2 + 2*j^2 + 3*k^2 with i,j,k >= 0, and fewer than m ways to write w = i^2 + 2*j^2 + 3*k^2 for every w < v.
EXAMPLE
a(6) = 7 is a term because 36 = 6^2 + 2*0^2 + 3*0^2 = 2^2 + 2*4^2 + 3*0^2
= 5^2 + 2*2^2 + 3*1^2 = 1^2 + 2*4^2 + 3*1^2 = 4^2 + 2*2^2 + 3*2^2 = 3^2 + 2*0^2 + 3*3^2 = 1^2 + 2*2^2 + 3*3^2 can be written as i^2 + 2*j^2 + 3*k^2 in 7 ways, and all numbers < 36 can be written in fewer than 7 ways.
MAPLE
g:= add(z^(i^2), i=0..500) * add(z^(2*i^2), i=0..floor(500/sqrt(2))) *
add(z^(3*i^2), i=0..floor(500/sqrt(3))):
S:= series(g, z, 250001):
L:= [seq(coeff(S, z, i), i=0..250000)]:
B:= NULL: m:= 0:
for i from 1 to 250001 do
if L[i] > m then
m:= L[i]; B:=B, m
fi
od:
B;
CROSSREFS
KEYWORD
nonn
AUTHOR
Robert Israel, Sep 28 2023
STATUS
approved