OFFSET
1,5
LINKS
Alois P. Heinz, Table of n, a(n) for n = 1..10000
MAPLE
with(numtheory):
a:= n-> mul(i, i=select(h-> irem(h, 4)=1, divisors(n))):
seq(a(n), n=1..120); # Alois P. Heinz, Jul 28 2009
MATHEMATICA
a[n_] := Times @@ Select[Divisors[n], Mod[#, 4] == 1&]; Table[a[n], {n, 1, 120}] (* Jean-François Alcover, Jun 24 2015 *)
PROG
(PARI) a(n) = my(p=1); fordiv(n, d, if ((d % 4)==1, p*=d)); p; \\ Michel Marcus, Jan 07 2021
CROSSREFS
KEYWORD
nonn,look
AUTHOR
R. J. Mathar, Jun 27 2008
EXTENSIONS
More terms from Alois P. Heinz, Jul 28 2009
STATUS
approved