A378987 Odd bisection of A083254, where A083254(n) = 2*phi(n)-n.

1, 1, 3, 5, 3, 9, 11, 1, 15, 17, 3, 21, 15, 9, 27, 29, 7, 13, 35, 9, 39, 41, 3, 45, 35, 13, 51, 25, 15, 57, 59, 9, 31, 65, 19, 69, 71, 5, 43, 77, 27, 81, 43, 25, 87, 53, 27, 49, 95, 21, 99, 101, -9, 105, 107, 33, 111, 61, 27, 73, 99, 37, 75, 125, 39, 129, 83, 9, 135, 137, 43, 97, 79, 21, 147, 149, 39, 85, 155, 49, 103, 161, -5, 165

Offset: 1

Author

Antti Karttunen, Dec 14 2024

Keywords

• sign

Links

• Antti Karttunen, Table of n, a(n) for n = 1..32769

Crossrefs

Cf. A000010, A083254, A064216, A337544.

Cf. also A378986 (the other bisection).

Programs

PARI

A083254(n) = (2*eulerphi(n)-n);
A378987(n) = A083254(n+n-1);

Formula

a(n) = A083254(2*n-1).

a(n) = A337544(A064216(n)).