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 1-6 of 6 results.

A245611 Permutation of natural numbers: a(n) = A243071(A064216(n)).

Original entry on oeis.org

0, 1, 3, 7, 2, 15, 31, 6, 63, 127, 14, 255, 5, 4, 511, 1023, 30, 13, 2047, 62, 4095, 8191, 12, 16383, 11, 126, 32767, 29, 254, 65535, 131071, 28, 61, 262143, 510, 524287, 1048575, 10, 27, 2097151, 8, 4194303, 125, 1022, 8388607, 59, 2046, 253, 16777215, 60, 33554431, 67108863, 26
Offset: 1

Views

Author

Antti Karttunen, Jul 28 2014

Keywords

Comments

Note the indexing: the domain starts from 1, while the range includes also zero.
The odd bisection of A243071 decremented by one and halved. (For a(1) = 0, take ceiling of -1/2).

Crossrefs

Programs

Formula

a(1) = 0, and for n > 1, a(n) = (1/2) * (A243071((2*n)-1) - 1).
As a composition of related permutations:
a(n) = A243071(A064216(n)).
a(n) = A054429(A244153(n)).

A244153 Permutation of natural numbers, the odd bisection of A156552 halved; equally, a composition of A064216 and A156552: a(n) = A156552(A064216(n)).

Original entry on oeis.org

0, 1, 2, 4, 3, 8, 16, 5, 32, 64, 9, 128, 6, 7, 256, 512, 17, 10, 1024, 33, 2048, 4096, 11, 8192, 12, 65, 16384, 18, 129, 32768, 65536, 19, 34, 131072, 257, 262144, 524288, 13, 20, 1048576, 15, 2097152, 66, 513, 4194304, 36, 1025, 130, 8388608, 35, 16777216, 33554432, 21, 67108864, 134217728, 2049, 268435456, 258, 67, 68, 24, 4097, 14
Offset: 1

Views

Author

Antti Karttunen, Jun 27 2014

Keywords

Comments

Note the indexing: the domain starts from 1, while the range includes also zero.

Crossrefs

Programs

Formula

a(n) = A156552(2n+1) / 2.
As a composition of related permutations:
a(n) = A156552(A064216(n)).
a(n) = A054429(A245611(n)).

A245607 Permutation of natural numbers, the even bisection of A245605 halved: a(n) = A245605(2*n)/2.

Original entry on oeis.org

1, 2, 3, 5, 4, 9, 13, 6, 17, 37, 8, 25, 7, 10, 69, 33, 26, 11, 41, 16, 277, 45, 18, 65, 21, 14, 1109, 15, 52, 73, 57, 74, 35, 209, 82, 293, 141, 34, 53, 329, 12, 1173, 31, 36, 213, 149, 104, 43, 49, 20, 145, 173, 138, 81, 581, 114, 553, 71, 90, 133, 101, 282, 19, 325, 24, 457, 165, 50, 77, 97, 62, 105, 555, 42
Offset: 1

Views

Author

Antti Karttunen, Jul 29 2014

Keywords

Crossrefs

Programs

Formula

a(n) = A245605(2*n)/2.
As a composition of related permutations:
a(n) = A245605(A064216(n)).
a(n) = A245705(A245707(n)).

A245608 Permutation of natural numbers, the even bisection of A245606 halved: a(n) = A245606(2*n)/2.

Original entry on oeis.org

1, 2, 3, 5, 4, 8, 13, 11, 6, 14, 18, 41, 7, 26, 28, 20, 9, 23, 63, 50, 25, 113, 313, 65, 12, 17, 88, 77, 172, 149, 43, 95, 16, 38, 33, 44, 10, 413, 163, 221, 19, 74, 48, 191, 22, 476, 118, 179, 49, 68, 138, 29, 39, 527, 78, 215, 31, 635, 1593, 227, 102, 71, 688, 242, 24, 122, 193, 104, 15, 98, 58, 176, 30, 32, 123
Offset: 1

Views

Author

Antti Karttunen, Jul 29 2014

Keywords

Crossrefs

Programs

Formula

a(n) = A245606(2*n)/2.
As a composition of related permutations:
a(n) = A048673(A245606(n)).
a(n) = A245708(A245706(n)).
Other identities:
For all n >= 0, a(2^n) = A245708(2^n). Moreover, A245709 gives all such k that a(k) = A245708(k).

A244319 Self-inverse permutation of natural numbers: a(1) = 1, a(2n) = A003961(1+a(A064989(2n-1))), a(2n+1) = 1+A003961(a(A064989(2n+1)-1)).

Original entry on oeis.org

1, 3, 2, 9, 6, 5, 26, 11, 4, 21, 8, 125, 56, 25, 16, 15, 344, 115, 36, 1015, 10, 39, 204, 41, 14, 7, 52, 45, 86, 301, 176, 155, 298, 51, 50, 19, 518, 305, 22, 189, 24, 895, 1376, 49, 28, 825, 1268, 11875, 44, 35, 34, 27, 3186, 6625, 2388, 13, 454, 153, 126, 3191, 476, 131
Offset: 1

Views

Author

Antti Karttunen, Jul 18 2014; description corrected and PARI code added Jul 30 2014

Keywords

Comments

After 1, maps each even number to a unique odd number and vice versa, i.e., for all n > 1, A000035(a(n)) XOR A000035(n) = 1, where XOR is given in A003987.

Crossrefs

Related permutations: A048673, A064216, A245609-A245610.
Similar entanglement permutations: A245605-A245606, A235491, A236854, A243347, A244152.

Programs

Formula

a(1) = 1, a(2n) = A003961(1+a(A064989(2n-1))), a(2n+1) = A243501(a(A064989(2n+1)-1)).
As a composition of related permutations:
a(n) = A245609(A048673(n)) = A064216(A245610(n)).

A245610 Permutation of natural numbers: a(n) = A048673(A244319(n)).

Original entry on oeis.org

1, 3, 2, 13, 8, 4, 26, 7, 5, 28, 14, 172, 149, 25, 41, 18, 635, 102, 113, 1194, 11, 43, 428, 22, 17, 6, 77, 88, 71, 259, 527, 130, 227, 48, 74, 12, 677, 235, 20, 688, 68, 634, 5711, 61, 50, 1593, 1490, 27612, 59, 39, 29, 63, 11438, 10119, 4748, 9, 344, 238, 413, 1602, 941, 69
Offset: 1

Views

Author

Antti Karttunen, Jul 29 2014

Keywords

Crossrefs

Programs

Formula

a(n) = A048673(A244319(n)).
Showing 1-6 of 6 results.