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A347249
a(n) = A331410(n) - A336361(n).
5
0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 1, 0, -1, -1, 0, 0, 1, 0, 0, 0, 2, 0, 0, 0, 1, 1, 0, 0, 1, -1, 1, -1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 0, 0, 0, -2, 2, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 2, 1, -1, -1, 1, 1, -1, -1, 0, 0, 3, 0, 1, 1, 0, 0, -1, 1, 1, 1, 1, 0, 2, 0, 1, 1, 1, 0, 1, 0, 2, 0, -2, -2, 1, 2
OFFSET
1,25
COMMENTS
Terms 0 .. 9 occur for the first time at n = 1, 15, 25, 75, 275, 725, 2175, 3725, 9025, 27075.
LINKS
FORMULA
a(n) = A331410(n) - A336361(n).
For all n >= 1, a(n) = a(2*n) = a(A000265(n)).
PROG
(PARI)
A331410(n) = { my(f=factor(n)); sum(k=1, #f~, if(2==f[k, 1], 0, f[k, 2]*(1+A331410(f[k, 1]+1)))); };
A336361(n) = if(!bitand(n, n-1), 0, 1+A336361(sigma(n>>valuation(n, 2))));
A347249(n) = (A331410(n)-A336361(n));
CROSSREFS
Cf. A000265, A331410, A336361, A347250 (positions of negative terms).
Cf. also A347374.
Sequence in context: A133703 A073265 A338326 * A025438 A220400 A285108
KEYWORD
sign
AUTHOR
Antti Karttunen, Aug 28 2021
STATUS
approved