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.

Previous Showing 11-15 of 15 results.

A048719 Binary expansion matches ((0)*0011)*(0*).

Original entry on oeis.org

0, 3, 6, 12, 24, 48, 51, 96, 99, 102, 192, 195, 198, 204, 384, 387, 390, 396, 408, 768, 771, 774, 780, 792, 816, 819, 1536, 1539, 1542, 1548, 1560, 1584, 1587, 1632, 1635, 1638, 3072, 3075, 3078, 3084, 3096
Offset: 0

Views

Author

Antti Karttunen, Mar 30 1999

Keywords

Comments

1-bits occur only in pairs, separated from other such pairs by at least two 0-bits.
All terms satisfy both A048727(n) = 3*n and A048725(n) = 5*n.

Crossrefs

Intersection of A048716 and A048717.

Programs

  • Mathematica
    filterQ[n_] := With[{bb = IntegerDigits[n, 2]}, !MatchQ[bb, {1}|{1, 0, _}|{_, 0, 1}|{_, 0, 1, 0, _}|{_, 1, 1, 1, _}|{_, 1, 0, 1, _}]];
    Select[Range[0, 3096], filterQ] (* Jean-François Alcover, Dec 31 2020 *)
  • PARI
    is(n)=n%3==0 && !bitand(n/3, 14*n/3) \\ Charles R Greathouse IV, Oct 03 2016

Formula

a(n) = 3*A048718(n).

A327972 Bitwise XOR of trajectories of rule 30 and rule 150, when both are started from a lone 1 cell: a(n) = A110240(n) XOR A038184(n).

Original entry on oeis.org

0, 0, 12, 4, 128, 384, 3404, 740, 37056, 127296, 794316, 286532, 8510656, 25560896, 224057484, 42076324, 2446214016, 8430013568, 51732969356, 18062215300, 553213409792, 1655549411840, 14630859361996, 3227756349540, 159219183713088, 546944274202816, 3411332163636556, 1231354981057220, 36554500089286208, 109782277571646400, 962314238681316620
Offset: 0

Views

Author

Antti Karttunen, Oct 03 2019

Keywords

Crossrefs

Cf. also A327971, A327973, A327976, A328103, A328104 for other such combinations.

Programs

Formula

a(n) = A038184(n) XOR A110240(n).
Conjecture: for n > 1, floor(log_2(a(n))) = 2*n - (1,2,1,4,1,2,1,5 according as n == 0..7 (mod 8), respectively). - Alan Michael Gómez Calderón, Mar 02 2023

A277199 Transpose of square array A277320.

Original entry on oeis.org

1, 2, 2, 7, 4, 3, 4, 14, 6, 4, 13, 8, 9, 8, 5, 14, 26, 12, 28, 10, 6, 11, 28, 23, 16, 27, 12, 7, 8, 22, 18, 52, 20, 18, 14, 8, 25, 16, 29, 56, 57, 24, 21, 16, 9, 26, 50, 24, 44, 54, 46, 28, 56, 18, 10, 31, 52, 43, 32, 39, 36, 35, 32, 63, 20, 11, 28, 62, 46, 100, 40, 58, 42, 104, 36, 54, 22, 12, 21, 56, 33, 104, 125, 48, 49, 112, 101, 40, 49, 24, 13
Offset: 1

Views

Author

Antti Karttunen, Nov 01 2016

Keywords

Comments

See A277320.

Examples

			The top left corner of the array:
   1,  2,  7,  4,  13,  14,  11,   8,  25,  26,  31,  28
   2,  4, 14,  8,  26,  28,  22,  16,  50,  52,  62,  56
   3,  6,  9, 12,  23,  18,  29,  24,  43,  46,  33,  36
   4,  8, 28, 16,  52,  56,  44,  32, 100, 104, 124, 112
   5, 10, 27, 20,  57,  54,  39,  40, 125, 114,  99, 108
   6, 12, 18, 24,  46,  36,  58,  48,  86,  92,  66,  72
   7, 14, 21, 28,  35,  42,  49,  56,  79,  70,  93,  84
   8, 16, 56, 32, 104, 112,  88,  64, 200, 208, 248, 224
   9, 18, 63, 36, 101, 126,  83,  72, 209, 202, 231, 252
  10, 20, 54, 40, 114, 108,  78,  80, 250, 228, 198, 216
  11, 22, 49, 44, 127,  98,  69,  88, 227, 254, 217, 196
  12, 24, 36, 48,  92,  72, 116,  96, 172, 184, 132, 144
		

Crossrefs

Transpose: A277320.
Main diagonal: A277699.
Row 1: A065621, Row 3: 3: A277823.
Column 1: A000027, Column 3: A048727.
Cf. A048720.

Programs

Formula

A(r,c) = A048720(r, A065621(c)).

A284555 Positions of zeros in A284557.

Original entry on oeis.org

0, 3, 5, 6, 7, 9, 10, 12, 14, 15, 18, 20, 24, 28, 30, 31, 33, 36, 40, 45, 48, 51, 56, 60, 62, 63, 66, 72, 77, 80, 83, 89, 90, 96, 99, 101, 102, 103, 107, 112, 115, 120, 124, 126, 127, 129, 132, 139, 144, 147, 153, 154, 160, 163, 165, 166, 167, 171, 178, 180, 187, 189, 192, 195, 197, 198, 199, 201, 202, 204, 206, 207
Offset: 0

Views

Author

Antti Karttunen, Apr 10 2017

Keywords

Comments

Indexing starts from zero, because a(0) = 0 is a special case in this list.

Crossrefs

Cf. A048717 (a subsequence).

A353168 Polynomials over GF(2) that are divisible by x^2+x+1, encoded as binary numbers.

Original entry on oeis.org

0, 7, 9, 14, 18, 21, 27, 28, 35, 36, 42, 45, 49, 54, 56, 63, 65, 70, 72, 79, 83, 84, 90, 93, 98, 101, 107, 108, 112, 119, 121, 126, 130, 133, 139, 140, 144, 151, 153, 158, 161, 166, 168, 175, 179, 180, 186, 189, 195, 196, 202, 205, 209, 214, 216, 223, 224, 231, 233
Offset: 1

Views

Author

Jack Zhang, Apr 28 2022

Keywords

Comments

Terms of A048727, sorted.

Crossrefs

Cf. A048727.
See also A001969 for those divisible by x + 1.

Programs

  • Python
    from itertools import count, chain, islice
    def A353168_gen(): # generator of terms
        return chain((0,),chain.from_iterable((sorted(n^ n<<1 ^ n<<2 for n in range(2**l,2**(l+1))) for l in count(0))))
    A353168_list = list(islice(A353168_gen(),30)) # Chai Wah Wu, Jun 29 2022

Extensions

More terms from David A. Corneth, Apr 28 2022
Previous Showing 11-15 of 15 results.