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A328803
The minimum value of j + k where j and k are positive integers with j^2 + k^2 = A001481(n).
3
0, 1, 2, 2, 3, 4, 3, 4, 5, 4, 5, 6, 6, 5, 6, 7, 8, 8, 6, 7, 8, 9, 9, 7, 8, 10, 9, 10, 11, 8, 9, 10, 12, 11, 12, 12, 9, 10, 11, 13, 12, 13, 14, 10, 11, 12, 14, 13, 15, 14, 15, 11, 12, 13, 16, 14, 16, 15, 12, 13, 16, 14, 17, 15, 17, 16, 18, 18, 13, 14, 15, 16
OFFSET
1,3
EXAMPLE
For n = 14, A001481(14) = 25 = 0^2 + 5^2 = 3^2 + 4^2, so a(14) = min{0+5, 3+4} = 5.
MAPLE
N:= 1000: # for terms where A001481(n)<=N
for s from 0 to isqrt(N) do
for i from 0 to s/2 do
t:= i^2 + (s-i)^2;
if t > N then break fi;
if not assigned(R[t]) then R[t]:= s fi;
od od:
A1481:= sort(map(op, [indices(R)])):
seq(R[i], i=A1481); # Robert Israel, Oct 28 2019
PROG
(Python)
from itertools import count, islice
from sympy.solvers.diophantine.diophantine import diop_DN
from sympy import factorint
def A328803_gen(): # generator of terms
return map(lambda n: min((a+b for a, b in diop_DN(-1, n))), filter(lambda n:(lambda m:all(d&3!=3 or m[d]&1==0 for d in m))(factorint(n)), count(0)))
A328803_list = list(islice(A328803_gen(), 30)) # Chai Wah Wu, Sep 09 2022
CROSSREFS
Sequence in context: A061282 A244040 A338913 * A328804 A064514 A112342
KEYWORD
nonn,look
AUTHOR
Peter Kagey, Oct 27 2019
STATUS
approved