cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A354102 a(n) = phi(A267099(n)), where A267099 is fully multiplicative involution swapping the positions of 4k+1 and 4k+3 primes, and phi is Euler totient function.

Original entry on oeis.org

1, 1, 4, 2, 2, 4, 12, 4, 20, 2, 16, 8, 6, 12, 8, 8, 10, 20, 28, 4, 48, 16, 36, 16, 6, 6, 100, 24, 18, 8, 40, 16, 64, 10, 24, 40, 22, 28, 24, 8, 30, 48, 52, 32, 40, 36, 60, 32, 156, 6, 40, 12, 42, 100, 32, 48, 112, 18, 72, 16, 46, 40, 240, 32, 12, 64, 88, 20, 144, 24, 96, 80, 58, 22, 24, 56, 192, 24, 100, 16, 500
Offset: 1

Views

Author

Antti Karttunen, May 18 2022

Keywords

Crossrefs

Möbius transform of A267099.
Cf. A000720, A008683, A267101, A354101, A354103, A354104 (Dirichlet inverse), A354105 (sum with it), A354106, A354107 (a(n) mod 4), A354190, A354191.
Coincides with A000010 on A354189.

Programs

Formula

Multiplicative with a(p^e) = (q-1) * q^(e-1), where q = A267101(A000720(p)).
a(n) = A000010(A267099(n)).
a(n) = Sum_{d|n} A008683(n/d) * A267099(d).
a(n) = A354101(n) + A000010(n) = A354190(n) - A354191(n).
For all n >= 0, a(4n+2) = a(2n+1).

A354191 a(n) = phi(A267099(sigma(n))) - phi(A267099(n)), where A267099 is fully multiplicative involution swapping the positions of 4k+1 and 4k+3 primes.

Original entry on oeis.org

0, 3, -2, 10, 2, 4, -8, 4, -14, 18, -8, 16, 6, 4, 8, 32, 10, 4, -24, 44, -32, 24, -20, 0, 34, 42, -92, 24, -10, 72, -24, 224, -32, 90, 8, 32, 6, -12, 24, 32, 18, 16, -20, 64, -16, 44, -28, 48, -44, 154, 40, 144, 58, -68, 48, -16, -96, 22, -56, 176, -6, 24, -216, 116, 84, 96, -68, 220, -80, 136, -16, -32, -36, 90
Offset: 1

Views

Author

Antti Karttunen, May 19 2022

Keywords

Crossrefs

Cf. A000010, A000203, A267099, A354102, A354106 (positions of 0's), A354190.
Cf. also A353636.

Programs

Formula

a(n) = A354190(n) - A354102(n).
Showing 1-2 of 2 results.