A326048 a(n) = gcd(n-A050449(n), A082052(n)-n), where A050449 and A082052 give the sum of divisors of the form 4k+1, and not of that form, respectively.

1, 1, 2, 1, 1, 5, 6, 1, 1, 2, 10, 1, 1, 1, 3, 1, 1, 1, 18, 2, 1, 1, 22, 1, 1, 2, 1, 27, 1, 12, 30, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 4, 42, 1, 3, 5, 46, 1, 1, 1, 3, 2, 1, 4, 1, 1, 1, 2, 58, 6, 1, 1, 2, 1, 1, 4, 66, 10, 1, 4, 70, 1, 1, 2, 2, 3, 1, 4, 78, 2, 1, 2, 82, 2, 1, 5, 3, 1, 1, 6, 7, 1, 1, 1, 1, 5, 1, 1, 14, 1, 1, 12, 102, 2, 9

Offset

1,3

Links

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

Formula

a(n) = gcd(A326049(n), A326050(n)) = gcd(n-A050449(n), A082052(n)-n).

a(2n-1) = A326047(2n-1) for all n.

Prog

(PARI)
A050449(n) = sumdiv(n, d, d*((d % 4) == 1)); \\ From A050449
A326049(n) = (n-A050449(n));
A082052(n) = sumdiv(n, d, if(1!=(d%4), d));
A326050(n) = (A082052(n)-n);
A326048(n) = gcd(A326049(n), A326050(n));

Crossrefs

Cf. A050449, A082052, A326047, A326049, A326050.

Cf. also A009194, A325385, A325813, A325975.

Sequence in context: A119687 A086856 A052916 * A156576 A293219 A266572

Adjacent sequences: A326045 A326046 A326047 * A326049 A326050 A326051

Keyword

nonn

Author

Antti Karttunen, Jun 04 2019

Status

approved