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A140213
Product_{h|n and h mod 6 = 1} h; product of divisors of n of the form 6*k + 1.
6
1, 1, 1, 1, 1, 1, 7, 1, 1, 1, 1, 1, 13, 7, 1, 1, 1, 1, 19, 1, 7, 1, 1, 1, 25, 13, 1, 7, 1, 1, 31, 1, 1, 1, 7, 1, 37, 19, 13, 1, 1, 7, 43, 1, 1, 1, 1, 1, 343, 25, 1, 13, 1, 1, 55, 7, 19, 1, 1, 1, 61, 31, 7, 1, 13, 1, 67, 1, 1, 7, 1, 1, 73, 37, 25, 19, 7, 13, 79, 1, 1, 1, 1, 7, 85, 43, 1, 1, 1, 1, 8281
OFFSET
1,7
LINKS
MAPLE
A140213 := proc(n)
a := 1;
for d in numtheory[divisors](n) do
if modp(d, 6) = 1 then
a := a*d ;
end if;
end do:
a;
end proc: # R. J. Mathar, Dec 15 2015
PROG
(PARI) A140213(n) = { my(m=1); fordiv(n, d, if(1==(d%6), m *= d)); (m); }; \\ Antti Karttunen, Jul 09 2017
CROSSREFS
KEYWORD
nonn,easy,look
AUTHOR
R. J. Mathar, Jun 27 2008
EXTENSIONS
More terms from D. S. McNeil, Mar 24 2009
STATUS
approved