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.

A207017 Numbers m for which there exists a number 1k, where operation <+> is defined in A206853.

Original entry on oeis.org

4, 7, 9, 11, 13, 14, 16, 18, 21, 22, 24, 26, 28, 31, 33, 35, 39, 41, 44, 46, 47, 49, 50, 53, 55, 56, 57, 59, 61, 62, 63, 66, 70, 73, 79, 82, 83, 84, 89, 93, 94, 96, 97, 102, 104, 110, 111, 112, 115, 116, 118, 120, 121, 122, 124, 125, 126, 127, 129, 131
Offset: 1

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Author

Vladimir Shevelev, Feb 14 2012

Keywords

Comments

It is natural to call terms of the sequence "Hamming composite numbers" and to say that m is "H-divisible" by k.

Examples

			127 = b_21 for k=2, b_16 for k=4 and b_8 for k=5. Thus 127 is H-divisible by 2, 4 and 5 (and only by them).
		

Crossrefs

A207460 Let a(1) = 4. For n > 1, a(n) is the least number greater than a(n-1) such that the Hamming distance D(a(n-1),a(n)) = 4.

Original entry on oeis.org

4, 11, 16, 31, 35, 44, 49, 62, 70, 73, 82, 93, 97, 110, 112, 127, 143, 145, 158, 162, 173, 176, 191, 199, 200, 211, 220, 224, 239, 241, 254, 286, 290, 301, 304, 319, 327, 328, 339, 348, 352, 367, 369, 382, 398, 400, 415, 419
Offset: 1

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Author

Vladimir Shevelev, Feb 18 2012

Keywords

Comments

All terms are odious (A000069).

Crossrefs

Programs

  • Mathematica
    nxt[n_]:=Module[{k=n+1},While[HammingDistance[PadLeft[IntegerDigits[ n,2],IntegerLength[ k,2]],IntegerDigits[k,2]]!=4,k++];k]; NestList[ nxt,4,50] (* Harvey P. Dale, Nov 07 2020 *)

A207472 Let a(1) = 5. For n > 1, a(n) is the least number greater than a(n-1) such that the Hamming distance D(a(n-1),a(n)) = 5.

Original entry on oeis.org

5, 26, 33, 62, 66, 93, 96, 127, 135, 152, 163, 188, 192, 223, 225, 254, 270, 273, 294, 313, 320, 351, 353, 382, 390, 409, 418, 445, 449, 478, 480, 511, 543, 545, 574, 578, 605, 608, 639, 647, 664, 675, 700, 704, 735, 737, 766, 782, 785, 806, 825, 832, 863, 865
Offset: 1

Views

Author

Vladimir Shevelev, Feb 18 2012

Keywords

Comments

Odious and evil terms are alternating (cf. A000069, A001969).

Crossrefs

Programs

  • Mathematica
    a[1] = 5; a[n_] := a[n] = Module[{k = a[n - 1], m = a[n-1] + 1}, While[DigitCount[BitXor[k, m], 2, 1] != 5, m++]; m]; Array[a, 100] (* Amiram Eldar, Aug 06 2023 *)
Showing 1-3 of 3 results.