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 1-10 of 56 results. Next

A178374 a(n) = A075930(n)^A178307(n).

Original entry on oeis.org

343, 1331, 169, 2744, 6859, 441, 10648, 390625, 676, 21952, 29791, 1500625, 1369, 54872, 68921, 1764, 85184, 2209, 5764801, 6250000, 2704, 166375, 175616, 714924299, 3721, 238328
Offset: 1

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Author

Jeremy Gardiner, May 26 2010

Keywords

Comments

a(n) is in A001969 for all n.

Examples

			A075930(1)=7, A178307(1)=3, a(1)=7^3=343.
		

Crossrefs

A075928 List of codewords in binary lexicode with Hamming distance 4 written as decimal numbers.

Original entry on oeis.org

0, 15, 51, 60, 85, 90, 102, 105, 150, 153, 165, 170, 195, 204, 240, 255, 771, 780, 816, 831, 854, 857, 869, 874, 917, 922, 934, 937, 960, 975, 1011, 1020, 1285, 1290, 1334, 1337, 1360, 1375, 1379, 1388, 1427, 1436, 1440, 1455, 1478, 1481, 1525
Offset: 0

Views

Author

Bob Jenkins (bob_jenkins(AT)burtleburtle.net)

Keywords

Comments

The lexicode of Hamming distance d is constructed greedily by stepping through the binary vectors in lexicographic order and accepting a vector if it is at Hamming distance at least d from all already-chosen vectors.
The code is linear and infinite.
This is also the (infinite) d=4 Hamming code.
Lexicodes with even Hamming distance can be constructed from the preceding lexicode of odd Hamming distance by prepending a single parity bit.

Crossrefs

A075926 List of codewords in binary lexicode with Hamming distance 3 written as decimal numbers.

Original entry on oeis.org

0, 7, 25, 30, 42, 45, 51, 52, 75, 76, 82, 85, 97, 102, 120, 127, 385, 390, 408, 415, 427, 428, 434, 437, 458, 461, 467, 468, 480, 487, 505, 510, 642, 645, 667, 668, 680, 687, 689, 694, 713, 718, 720, 727, 739, 740, 762, 765, 771, 772, 794, 797, 809
Offset: 0

Views

Author

Bob Jenkins (bob_jenkins(AT)burtleburtle.net)

Keywords

Comments

This is also the (infinite) d=3 Hamming code.

Crossrefs

A075931 List of codewords in binary lexicode with Hamming distance 5 written as decimal numbers.

Original entry on oeis.org

0, 31, 227, 252, 805, 826, 966, 985, 1354, 1365, 1449, 1462, 1647, 1648, 1676, 1683, 6182, 6201, 6341, 6362, 6915, 6940, 7136, 7167, 7532, 7539, 7567, 7568, 7753, 7766, 7850, 7861, 10315, 10324, 10408, 10423, 11118, 11121, 11149, 11154
Offset: 0

Views

Author

Bob Jenkins (bob_jenkins(AT)burtleburtle.net)

Keywords

Crossrefs

Programs

  • PARI
    a=vector(40); n=0; for (k=0, 11154, if (n==0 || vecmin(apply(o -> hammingweight(bitxor(k, o)), a[1..n]))>=5, print1 (a[n++]=k", "))) \\ Rémy Sigrist, Feb 09 2021

A075934 List of codewords in binary lexicode with Hamming distance 6 written as decimal numbers.

Original entry on oeis.org

0, 63, 455, 504, 1611, 1652, 1932, 1971, 2709, 2730, 2898, 2925, 3294, 3297, 3353, 3366, 12365, 12402, 12682, 12725, 13830, 13881, 14273, 14334, 15064, 15079, 15135, 15136, 15507, 15532, 15700, 15723, 20630, 20649, 20817, 20846, 22237
Offset: 0

Views

Author

Bob Jenkins (bob_jenkins(AT)burtleburtle.net)

Keywords

Crossrefs

A075937 List of codewords in binary lexicode with Hamming distance 7 written as decimal numbers.

Original entry on oeis.org

0, 127, 1927, 2040, 6553, 6630, 7710, 7777, 10922, 10965, 11565, 11602, 13107, 13132, 13492, 13515, 19252, 19275, 19635, 19660, 21165, 21202, 21802, 21845, 24990, 25057, 26137, 26214, 30727, 30840, 32640, 32767, 98731, 98772, 99884
Offset: 0

Views

Author

Bob Jenkins (bob_jenkins(AT)burtleburtle.net)

Keywords

References

  • J. H. Conway and N. J. A. Sloane, Lexicographic codes: error-correcting codes from game theory, IEEE Transactions on Information Theory, 32:337-348, 1986.

Crossrefs

Programs

  • C
    See Links section.

A075944 Basis for code in A075943.

Original entry on oeis.org

511, 15887, 116275, 412245, 693418, 3165290, 12603032, 21139155, 38803550, 201349286, 336626733, 609260174, 3221261509, 5374090380, 25769843817, 43016936625, 78384372260, 412317013686, 687266122367, 1238028666383
Offset: 0

Views

Author

Bob Jenkins (bob_jenkins(AT)burtleburtle.net)

Keywords

References

  • J. H. Conway and N. J. A. Sloane, Lexicographic codes: error-correcting codes from game theory, IEEE Transactions on Information Theory, 32:337-348, 1986.

Crossrefs

Formula

a(n) = b(2^n), where b is A075943, the binary lexicode, d=9.
b(n) = XOR(a(i)) for all i where the i-th bit is set in n.

A075945 Positions of check bits in code in A075943.

Original entry on oeis.org

255, 3855, 13107, 21845, 27306, 38506, 71576, 92115, 101470, 138406, 172589, 240014, 272069, 380556, 536169, 679601, 847140, 1072054, 1258879, 1397519, 2005450, 2121415, 2496892, 2738813, 3993667, 4241896, 4617503, 5821704
Offset: 0

Views

Author

Bob Jenkins (bob_jenkins(AT)burtleburtle.net)

Keywords

References

  • J. H. Conway and N. J. A. Sloane, Lexicographic codes: error-correcting codes from game theory, IEEE Transactions on Information Theory, 32:337-348, 1986.

Crossrefs

A075946 List of codewords in binary lexicode with Hamming distance 10 written as decimal numbers.

Original entry on oeis.org

0, 1023, 31775, 32736, 232551, 233368, 258168, 258951, 824491, 825172, 846004, 846667, 989388, 990003, 1008851, 1009452, 1386837, 1387178, 1398090, 1398453, 1484082, 1484493, 1497389, 1497810, 1687038, 1687041, 1688033
Offset: 0

Views

Author

Bob Jenkins (bob_jenkins(AT)burtleburtle.net)

Keywords

References

  • J. H. Conway and N. J. A. Sloane, Lexicographic codes: error-correcting codes from game theory, IEEE Transactions on Information Theory, 32:337-348, 1986.

Crossrefs

A075949 List of codewords in binary lexicode with Hamming distance 11 written as decimal numbers.

Original entry on oeis.org

0, 2047, 129055, 131040, 932067, 933660, 1032444, 1033987, 3299692, 3301011, 3383667, 3384972, 3957135, 3958384, 4037008, 4038255, 5548725, 5549386, 5591722, 5592405, 5935702, 5936553, 5990985, 5991862, 6747097, 6747174
Offset: 0

Views

Author

Bob Jenkins (bob_jenkins(AT)burtleburtle.net)

Keywords

References

  • J. H. Conway and N. J. A. Sloane, Lexicographic codes: error-correcting codes from game theory, IEEE Transactions on Information Theory, 32:337-348, 1986.

Crossrefs

Showing 1-10 of 56 results. Next