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.

Showing 1-5 of 5 results.

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).

A354189 Numbers k for which phi(A267099(k)) is equal to phi(k), 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, 2, 4, 8, 15, 16, 30, 32, 35, 39, 60, 64, 70, 78, 91, 120, 128, 140, 156, 182, 187, 225, 240, 256, 280, 312, 364, 374, 450, 480, 512, 551, 560, 624, 728, 748, 851, 900, 960, 1024, 1102, 1120, 1248, 1271, 1365, 1456, 1496, 1702, 1800, 1920, 2048, 2204, 2240, 2279, 2496, 2542, 2730, 2747, 2759, 2805, 2867, 2912, 2992
Offset: 1

Views

Author

Antti Karttunen, May 19 2022

Keywords

Comments

Not a subsequence of A072202. The first term that is included here, but not in that sequence is 69037, as A000010(69037) = A354102(69037) = 62400, although 69037 = 17*31*131. See A354194.

Crossrefs

Positions of zeros in A354101.
Subsequence of A354109.
Cf. A000079, A354192, A354194 (subsequences), A354188 (characteristic function).

Programs

Formula

{k | A354102(k) == A000010(k)}.

A354107 a(n) = A354102(n) mod 4.

Original entry on oeis.org

1, 1, 0, 2, 2, 0, 0, 0, 0, 2, 0, 0, 2, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 2, 2, 0, 0, 2, 0, 0, 0, 0, 2, 0, 0, 2, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 2, 0, 0, 0, 0, 2, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 2, 0, 0, 0, 0, 2, 0, 0, 2, 0, 0, 0, 2, 0, 0
Offset: 1

Views

Author

Antti Karttunen, May 18 2022

Keywords

Crossrefs

Programs

Formula

a(n) = A010873(A354102(n)).
a(n) = A353768(A267099(n)).

A354362 Intersection of A228058 and A260021.

Original entry on oeis.org

45, 49005, 597861, 715473, 1538757, 1891593, 1893213, 2714877, 3067713, 3890997, 4126221, 4479057, 5302341, 5465313, 5793525, 5890437, 6008013, 6478461, 6596073, 6882525, 7184133, 7419357, 8595477, 9771597, 10712493, 11300553, 11771001, 11888613, 12123837, 12947121, 13535181, 14240853, 15887421, 16240257, 17181153
Offset: 1

Views

Author

Antti Karttunen, May 24 2022

Keywords

Crossrefs

Subsequence of A353679.
Cf. also A354106.

Programs

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 1-5 of 5 results.