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A349569
Dirichlet convolution of A000027 (identity function) with A349452 (Dirichlet inverse of A011782, 2^(n-1)).
6
1, 0, -1, -4, -11, -24, -57, -112, -243, -480, -1013, -1964, -4083, -8064, -16309, -32496, -65519, -130440, -262125, -523156, -1048263, -2095104, -4194281, -8383760, -16777015, -33546240, -67107609, -134200860, -268435427, -536835096, -1073741793, -2147417216, -4294962187, -8589803520, -17179867533, -34359463812
OFFSET
1,4
COMMENTS
Dirichlet convolution with A034729 gives sigma, A000203, and convolution with A034738 gives A018804.
LINKS
FORMULA
a(n) = Sum_{d|n} d * A349452(n/d).
MATHEMATICA
s[1] = 1; s[n_] := s[n] = -DivisorSum[n, s[#]*2^(n/# - 1) &, # < n &]; a[n_] := DivisorSum[n, # * s[n/#] &]; Array[a, 36] (* Amiram Eldar, Nov 22 2021 *)
PROG
(PARI)
A011782(n) = (2^(n-1));
memoA349452 = Map();
A349452(n) = if(1==n, 1, my(v); if(mapisdefined(memoA349452, n, &v), v, v = -sumdiv(n, d, if(d<n, A011782(n/d)*A349452(d), 0)); mapput(memoA349452, n, v); (v)));
A349569(n) = sumdiv(n, d, d * A349452(n/d));
CROSSREFS
Cf. A000027, A011782, A349452, A349570 (Dirichlet inverse).
Sequence in context: A159350 A159348 A159349 * A349570 A192597 A181946
KEYWORD
sign
AUTHOR
Antti Karttunen, Nov 22 2021
STATUS
approved