A353467 a(1) = 1, for n > 1, a(n) = -Sum_{d|n, d<n} a(A252463(n/d)) * a(d).

1, -1, 1, 2, -1, -3, 1, -5, -1, 3, -1, 10, 1, -3, 1, 14, -1, 0, 1, -10, -1, 3, -1, -35, 2, -3, 2, 10, 1, 3, -1, -42, 1, 3, -3, 10, 1, -3, -1, 35, -1, -3, 1, -10, -3, 3, -1, 126, -1, -9, 1, 10, 1, -1, 3, -35, -1, -3, -1, -30, 1, 3, 3, 132, -3, 3, -1, -10, 1, 15, 1, -70, -1, -3, -1, 10, 1, -3, 1, -126, -5, 3, -1, 30

Offset

1,4

Links

Antti Karttunen, Table of n, a(n) for n = 1..16384

Index entries for sequences computed from indices in prime factorization

Formula

a(1) = 1, for n > 1, a(n) = -Sum_{d|n, d<n} A353468(n/d) * a(d).

For all n >= 1, a(A000040(n)) = ((-1)^n).

Prog

(PARI)
A252463(n) = if(!(n%2), n/2, my(f=factor(n)); for(i=1, #f~, f[i, 1] = precprime(f[i, 1]-1)); factorback(f));
memoA353467 = Map();
A353467(n) = if(1==n, 1, my(v); if(mapisdefined(memoA353467, n, &v), v, v = -sumdiv(n, d, if(d<n, A353467(A252463(n/d))*A353467(d), 0)); mapput(memoA353467, n, v); (v)));

Crossrefs

Cf. A000040, A252463, A353468 [Dirichlet inverse, also a(A252463(n))], A353469 [sum with it].

Cf. also A353457.

Sequence in context: A079068 A133021 A131208 * A168008 A178810 A374237

Adjacent sequences: A353464 A353465 A353466 * A353468 A353469 A353470

Keyword

sign

Author

Antti Karttunen, Apr 21 2022

Status

approved