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 1-3 of 3 results.

A378230 Positions of 0's in A378226, where A278226 is XOR-Moebius transform of A318457, and A318457(n) = n XOR (sigma(n)-n).

Original entry on oeis.org

6, 14, 28, 42, 50, 62, 72, 114, 124, 150, 186, 248, 254, 376, 402, 412, 426, 434, 474, 496, 498, 508, 762, 784, 786, 796, 868, 938, 978, 994, 1002, 1016, 1302, 1528, 1568, 1578, 1626, 1778, 1834, 1852, 1888, 1948, 1988, 2032, 3056, 3064, 3094, 3282, 3350, 3556, 3568, 3644, 3682, 3794, 3858, 3868, 3882, 3954, 4064
Offset: 1

Views

Author

Antti Karttunen, Nov 26 2024

Keywords

Crossrefs

Positions of 0's in A378226.
Subsequences: A000396 (at least the even terms).

Programs

A378441 Fixed points of A378226, where A278226 is XOR-Moebius transform of A318457, and A318457(n) = n XOR (sigma(n)-n).

Original entry on oeis.org

1, 2, 3, 4, 5, 7, 8, 11, 13, 16, 17, 19, 23, 27, 29, 31, 32, 37, 41, 43, 47, 53, 59, 61, 64, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 125, 127, 128, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 243, 251, 256, 257, 263, 269, 271, 277, 281
Offset: 1

Views

Author

Antti Karttunen, Nov 26 2024

Keywords

Crossrefs

Cf. A000040 (subsequence), A001065, A003987, A318457, A378226.

Programs

Formula

{k such that A378226(k) is equal to k}.

A378227 XOR-Moebius transform of A318467, where A318467(n) = 2*n XOR sigma(n).

Original entry on oeis.org

3, 4, 1, 8, 15, 6, 5, 16, 29, 14, 25, 12, 23, 6, 11, 32, 51, 30, 49, 12, 13, 22, 53, 24, 33, 14, 1, 12, 39, 126, 29, 64, 105, 70, 127, 20, 111, 70, 99, 24, 123, 58, 121, 12, 15, 38, 109, 48, 93, 30, 31, 28, 95, 22, 51, 24, 17, 14, 73, 172, 71, 6, 1, 128, 205, 114, 193, 140, 221, 102, 197, 72, 219, 142, 205, 108
Offset: 1

Views

Author

Antti Karttunen, Nov 26 2024

Keywords

Comments

Unique sequence satisfying SumXOR_{d divides n} a(d) = A318467(n) for all n > 0, where SumXOR is the analog of summation under the binary XOR operation. See A295901 for a list of some of the properties of Xor-Moebius transform.

Crossrefs

Programs

  • PARI
    A318467(n) = bitxor(2*n, sigma(n));
    A378227(n) = { my(v=0); fordiv(n, d, if(issquarefree(n/d), v=bitxor(v, A318467(d)))); (v); }

Formula

a(n) = 2*A256739(n) XOR A296203(n).
Showing 1-3 of 3 results.