OFFSET
1,4
COMMENTS
a(n) depends only on prime signature of n (cf. A025487). So a(24) = a(375) since 24 = 2^3 * 3 and 375 = 3 * 5^3 both have prime signature (3,1).
LINKS
FORMULA
MAPLE
read(transforms) :
L := [1] :
for n from 2 to 100 do
if isA050376(n) then
L := [op(L), -1] ;
else
L := [op(L), 0] ;
end if;
end do :
a050379 := DIRICHLETi(L) ; # R. J. Mathar, May 26 2017
PROG
(PARI)
A064547(n) = {my(f = factor(n)[, 2]); sum(k=1, #f, hammingweight(f[k])); } \\ Michel Marcus, Feb 10 2016
isA050376(n) = ((1==omega(n)) && (1==A064547(n))); \\ Checking that omega(n) is 1 is just an optimization here.
A050379(n) = if(1==n, n, sumdiv(n, d, if(d<n, isA050376(n/d)*A050379(d), 0))); \\ Antti Karttunen, Oct 20 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Christian G. Bower, Nov 15 1999
STATUS
approved