A349342 Sum of A026741 and its Dirichlet inverse.

2, 0, 0, 1, 0, 6, 0, 3, 9, 10, 0, 9, 0, 14, 30, 7, 0, 9, 0, 15, 42, 22, 0, 15, 25, 26, 27, 21, 0, 0, 0, 15, 66, 34, 70, 18, 0, 38, 78, 25, 0, 0, 0, 33, 45, 46, 0, 27, 49, 25, 102, 39, 0, 27, 110, 35, 114, 58, 0, 15, 0, 62, 63, 31, 130, 0, 0, 51, 138, 0, 0, 36, 0, 74, 75, 57, 154, 0, 0, 45, 81, 82, 0, 21, 170, 86

Offset

1,1

Links

Antti Karttunen, Table of n, a(n) for n = 1..20000

Formula

a(n) = A026741(n) + A349341(n).

a(1) = 2, and for n > 1, a(n) = -Sum_{d|n, 1<d<n} A026741(d) * A349341(n/d).

Prog

(PARI)
A026741(n) = if(n%2, n, n/2);
A349341(n) = { my(f = factor(n)); prod(i=1, #f~, if(2==f[i, 1], -1, if(1==f[i, 2], -f[i, 1], 0))); };
A349342(n) = (A026741(n)+A349341(n));

Crossrefs

Cf. A026741, A349341.

Sequence in context: A158785 A346243 A349916 * A365712 A349914 A354105

Adjacent sequences: A349339 A349340 A349341 * A349343 A349344 A349345

Keyword

nonn

Author

Antti Karttunen, Nov 15 2021

Status

approved