A354101 a(n) = phi(A267099(n)) - phi(n), where A267099 is fully multiplicative involution swapping the positions of 4k+1 and 4k+3 primes, and phi is Euler totient function.

0, 0, 2, 0, -2, 2, 6, 0, 14, -2, 6, 4, -6, 6, 0, 0, -6, 14, 10, -4, 36, 6, 14, 8, -14, -6, 82, 12, -10, 0, 10, 0, 44, -6, 0, 28, -14, 10, 0, -8, -10, 36, 10, 12, 16, 14, 14, 16, 114, -14, 8, -12, -10, 82, -8, 24, 76, -10, 14, 0, -14, 10, 204, 0, -36, 44, 22, -12, 100, 0, 26, 56, -14, -14, -16, 20, 132, 0, 22, -16

Offset

1,3

Links

Antti Karttunen, Table of n, a(n) for n = 1..19683

Formula

a(n) = A354102(n) - A000010(n) = A000010(A267099(n)) - A000010(n).

Prog

(PARI) A354101(n) = (eulerphi(A267099(n)) - eulerphi(n)); \\ Uses the program given in A267099.

Crossrefs

Cf. A000010, A267099, A354102, A354189 (positions of 0's).

Sequence in context: A171936 A071055 A183034 * A078052 A056458 A322509

Adjacent sequences: A354098 A354099 A354100 * A354102 A354103 A354104

Keyword

sign,look

Author

Antti Karttunen, May 19 2022

Status

approved