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 1-4 of 4 results.

A165819 a(n) = the smallest positive integer that, when written in binary, contains both binary n and binary 2n-1 as substrings.

Original entry on oeis.org

1, 6, 11, 28, 37, 22, 29, 120, 137, 83, 43, 92, 205, 59, 61, 496, 529, 291, 595, 167, 169, 86, 183, 376, 793, 410, 437, 220, 925, 123, 125, 2016, 2081, 1091, 2211, 583, 293, 1227, 2471, 2536, 2601, 339, 171, 2796, 729, 366, 751, 1520, 3121, 1586, 1637, 1652
Offset: 1

Views

Author

Leroy Quet, Sep 28 2009

Keywords

Comments

If a(n) in binary was instead to contain binary n and binary 2n+1 as substrings, then a(n) would = 2n+1 for all n.

Crossrefs

Formula

a(n) = A294977(n, 2*n-1). - Rémy Sigrist, Mar 03 2018

Extensions

More terms from Carl R. White, Oct 06 2009

A165820 a(n) = the smallest positive integer that, when written in binary, contains both binary n and binary n^2 as substrings.

Original entry on oeis.org

1, 4, 19, 16, 89, 100, 113, 64, 593, 1380, 377, 400, 425, 452, 481, 256, 4385, 1298, 723, 10640, 5561, 11748, 8471, 18456, 1649, 1700, 729, 1808, 1865, 1924, 1985, 1024, 33857, 9250, 36041, 75024, 5477, 11558, 40433, 83520, 1681, 87780, 22329, 92048
Offset: 1

Views

Author

Leroy Quet, Sep 28 2009

Keywords

Crossrefs

Programs

  • Mathematica
    f[n_] := Block[{k = 1, is = IntegerString[n, 2], iss = IntegerString[n^2, 2]}, While[ StringPosition[ IntegerString[k, 2], is] == {} || StringPosition[ IntegerString[k, 2], iss] == {}, k++ ]; k]; Array[f, 44] (* Robert G. Wilson v, Oct 02 2009 *)

Formula

a(n) = A294977(n, n^2). - Rémy Sigrist, Mar 03 2018

Extensions

a(7)-a(44) from Robert G. Wilson v, Oct 02 2009

A165821 a(n) = the smallest positive integer that, when written in binary, contains both binary n and the binary representation of the n-th prime as substrings.

Original entry on oeis.org

2, 6, 11, 28, 11, 13, 71, 152, 151, 58, 95, 101, 105, 174, 47, 848, 571, 978, 1075, 327, 1173, 719, 1335, 1432, 1561, 1626, 827, 860, 237, 241, 127, 131, 4233, 139, 4501, 1175, 4765, 2467, 167, 1384, 5299, 362, 703, 705, 1581, 1479, 3027, 3568, 227, 229
Offset: 1

Views

Author

Leroy Quet, Sep 28 2009

Keywords

Crossrefs

Formula

a(n) = A294977(n, A000040(n)). - Rémy Sigrist, Mar 03 2018

Extensions

More terms from Carl R. White, Oct 06 2009

A165822 a(n) = the smallest positive integer that, when written in binary, contains both binary n and the binary representation of the n-th Fibonacci number as substrings.

Original entry on oeis.org

1, 2, 6, 12, 5, 24, 29, 168, 137, 442, 89, 400, 233, 377, 7778, 15792, 1597, 18968, 66899, 6765, 10946, 181551, 28657, 1483800, 206097, 121393, 458562, 317811, 514229, 3977768, 21540319, 2178309, 56393249, 72811751, 9227465, 618910128
Offset: 1

Views

Author

Leroy Quet, Sep 28 2009

Keywords

Crossrefs

Formula

a(n) = A294977(n, A000045(n)). - Rémy Sigrist, Mar 03 2018

Extensions

More terms from Carl R. White, Oct 06 2009
Showing 1-4 of 4 results.