OFFSET
1,2
COMMENTS
a(n) / A083481(n) is either 2 or 1/2 depending on A136480(n) being even or odd, which is indicated by A039963(n).
a(n) = 1 for n>0 in A001108. - Michel Marcus, Mar 22 2023
MAPLE
a:= n-> mul(i[1]^irem(i[2], 2), i=ifactors(n*(n+1)/2)[2]):
seq(a(n), n=1..70); # Alois P. Heinz, Mar 20 2023
PROG
(Python)
from sympy.ntheory.factor_ import core
def A361670(n): return core(n*(n+1)>>1) # Chai Wah Wu, Mar 20 2023
(PARI) a(n) = core(n*(n+1)/2); \\ Michel Marcus, Mar 22 2023
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
R. J. Mathar, Mar 20 2023
STATUS
approved