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 18 results. Next

A011745 A binary m-sequence: expansion of reciprocal of x^32 + x^28 + x^27 + x + 1 (mod 2, shifted by 31 initial 0's).

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0
Offset: 0

Views

Author

Keywords

Comments

Periodic with period 2^32-1 = 3*5*17*257*65537 = 4294967295. - M. F. Hasler, Feb 17 2018

References

  • S. W. Golomb, Shift-Register Sequences, Holden-Day, San Francisco, 1967.
  • H. D. Lueke, Korrelationssignale, Springer 1992, pp. 43-48.
  • F. J. MacWilliams and N. J. A. Sloane, The Theory of Error-Correcting Codes, Elsevier/North Holland, 1978, p. 408.

Crossrefs

Cf. A011655..A011744 for other binary m-sequences, and A011746..A011751 for similar expansions over GF(2).

Programs

  • Mathematica
    Join[Table[0, 31], Mod[CoefficientList[1/(x^32 + x^28 + x^27 + x + 1) + O[x]^50, x], 2]] (* Jean-François Alcover, Feb 23 2018 *)
  • PARI
    A011745_vec=concat([1..31]*0,Vec(1/(x^32+x^28+x^27+x+1)+O(x^99))%2)
    A=matrix(N=32,N,i,j,if(i>1,i==j+1,setsearch([1,27,28,N],j)))*Mod(1,2);
    A011745(n)=lift((A^(n-#A+1))[1,1]) \\ M. F. Hasler, Feb 17 2018

Extensions

Edited by M. F. Hasler, Feb 17 2018

A088002 Expansion of (1+x^2)/(1+x^2+x^5).

Original entry on oeis.org

1, 0, 0, 0, 0, -1, 0, 1, 0, -1, 1, 1, -2, -1, 3, 0, -4, 2, 5, -5, -5, 9, 3, -14, 2, 19, -11, -22, 25, 20, -44, -9, 66, -16, -86, 60, 95, -126, -79, 212, 19, -307, 107, 386, -319, -405, 626, 298, -1012, 21, 1417, -647, -1715, 1659, 1694, -3076, -1047, 4791, -612, -6485, 3688, 7532, -8479, -6920, 14964, 3232
Offset: 0

Views

Author

N. J. A. Sloane, Nov 02 2003

Keywords

Crossrefs

Cf. A011746.

Programs

  • Maple
    f:= gfun:-rectoproc({a(n+5)=-a(n)-a(n+3),a(0)=1,
    seq(a(i)=0,i=1..4)},a(n),remember):
    map(f, [$1..100]); # Robert Israel, Jul 18 2016
  • Mathematica
    CoefficientList[Series[(1+x^2)/(1+x^2+x^5),{x,0,80}],x] (* or *) LinearRecurrence[ {0,-1,0,0,-1},{1,0,0,0,0},80] (* Harvey P. Dale, Jan 08 2023 *)
  • PARI
    Vec((1+x^2)/(1+x^2+x^5)+O(x^99)) \\ Charles R Greathouse IV, Sep 26 2012

A011744 A binary m-sequence: expansion of reciprocal of x^31 + x^3 + 1 (mod 2, shifted by 30 initial 0's).

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0
Offset: 0

Views

Author

Keywords

Comments

Periodic with period 2^31-1 = 2147483647. - M. F. Hasler, Feb 17 2018

References

  • S. W. Golomb, Shift-Register Sequences, Holden-Day, San Francisco, 1967.
  • H. D. Lueke, Korrelationssignale, Springer 1992, pp. 43-48.
  • F. J. MacWilliams and N. J. A. Sloane, The Theory of Error-Correcting Codes, Elsevier/North Holland, 1978, p. 408.

Crossrefs

Cf. A011655, A011656, ..., A011745 for other binary m-sequences, and A011746..A011751 for similar expansions over GF(2).

Programs

  • Mathematica
    Join[Table[0, 30], Mod[CoefficientList[1/(x^31+x^3+1) + O[x]^52, x], 2]] (* Jean-François Alcover, Feb 23 2018 *)
  • PARI
    A011744_vec=concat([1..31]*0,Vec(1/(x^32+x^28+x^27+x+1)+O(x^99))%2)
    A=matrix(31,31,i,j,if(i>1,i==j+1,setsearch([3,31],j)>0))*Mod(1,2);
    A011744(n)=lift((A^(n-30))[1,1]) \\ M. F. Hasler, Feb 17 2018

A011724 A binary m-sequence: expansion of reciprocal of x^11 + x^2 + 1 (mod 2, shifted by 10 initial 0's).

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 0, 1, 0, 0, 1, 1, 1, 0, 0, 1, 0, 1, 1, 1, 1, 0, 0, 1, 0, 1, 1, 1, 0, 0, 1, 1, 1, 1, 0, 1, 1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0
Offset: 0

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Author

Keywords

Comments

Sequence is 2047-periodic. - Ray Chandler, Dec 10 2016
Expansion of x^10/(x^11+x^2+1) over GF(2). Indeed, 2047 is the smallest k > 0 such that (1-x^k) == 0 (mod 1+x^2+x^11, 2), which means that 1/(1+x^2+x^11) is 2047-periodic over GF(2). It appears somewhat nontrivial that the coefficients of x^2037 through x^2046 of 1/(1+x^2+x^11) are zero (mod 2), which "justifies" the shift by 10 leading zeros. - M. F. Hasler, Feb 16 2018

References

  • S. W. Golomb, Shift-Register Sequences, Holden-Day, San Francisco, 1967.
  • H. D. Lueke, Korrelationssignale, Springer 1992, pp. 43-48.
  • F. J. MacWilliams and N. J. A. Sloane, The Theory of Error-Correcting Codes, Elsevier/North Holland, 1978, p. 408.

Crossrefs

Cf. A011655, A011656, ..., A011745 for other binary m-sequences, and A011746..A011751 for similar expansions over GF(2).

Programs

  • Maple
    for i from 0 to 9 do a[i]:= 0 od: a[10]:= 1:
    for i from 11 to 200 do a[i]:= a[i-2]+a[i-11] mod 2 od:
    seq(a[i],i=0..200); # Robert Israel, Feb 18 2018
  • Mathematica
    Join[Table[0, 10], Mod[CoefficientList[1/(x^11+x^2+1) + O[x]^72, x], 2]] (* Jean-François Alcover, Feb 23 2018 *)
  • PARI
    A011724_vec=Vec(lift(Mod(1,2)/(1+x^2+x^11)+O(x^2037)),-2047);
    A011724(n)=A011724_vec[n%2047+1] \\ Faster than polcoeff(...). - M. F. Hasler, Feb 17 2018

Formula

G.f. = x^10/(1+x^2+x^11) over GF(2). - M. F. Hasler, Feb 17 2018
a(n) == a(n-2) + a(n-11) (mod 2) for n >= 11. - Robert Israel, Feb 18 2018

A011727 A binary m-sequence: expansion of reciprocal of x^14 + x^12 + x^11 + x + 1 (mod 2, shifted by 13 initial 0's).

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 1, 0, 0, 1, 1, 1, 1, 0, 1, 1, 0, 1, 0, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 1, 0, 1, 0, 1, 1, 0, 1, 0, 0, 0, 0
Offset: 0

Views

Author

Keywords

Comments

Sequence is 16383-periodic. - Ray Chandler, Dec 10 2016

References

  • S. W. Golomb, Shift-Register Sequences, Holden-Day, San Francisco, 1967.
  • H. D. Lueke, Korrelationssignale, Springer 1992, pp. 43-48.
  • F. J. MacWilliams and N. J. A. Sloane, The Theory of Error-Correcting Codes, Elsevier/North Holland, 1978, p. 408.

Crossrefs

Cf. A011655..A011745 for other binary m-sequences, and A011746..A011751 for similar expansions over GF(2).

Programs

  • Mathematica
    Mod[#, 2] & /@ CoefficientList[Series[x^13/(x^14 + x^12 + x^11 + x + 1), {x, 0, 105}], x] (* Michael De Vlieger, Feb 21 2018 *)
  • PARI
    A011727_vec(N)=Vec(lift(Mod(1,2)/(x^14+x^12+x^11+x+1)+O(x^(N-13))),-N) \\ M. F. Hasler, Feb 17 2018

Formula

G.f. = x^13/(x^14 + x^12 + x^11 + x + 1) over GF(2). - M. F. Hasler, Feb 17 2018

A011738 A binary m-sequence: expansion of reciprocal of x^25 + x^3 + 1 (mod 2, shifted by 24 initial 0's).

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 1, 1, 1, 0, 1, 1, 1, 0
Offset: 0

Views

Author

Keywords

Comments

Sequence is 2^25-1 = 33554431-periodic. - M. F. Hasler, Feb 17 2018

References

  • S. W. Golomb, Shift-Register Sequences, Holden-Day, San Francisco, 1967.
  • H. D. Lueke, Korrelationssignale, Springer 1992, pp. 43-48.
  • F. J. MacWilliams and N. J. A. Sloane, The Theory of Error-Correcting Codes, Elsevier/North Holland, 1978, p. 408.

Crossrefs

Cf. A011655..A011745 for other binary m-sequences, and A011746..A011751 for similar expansions over GF(2).

Programs

  • Maple
    N:= 200: # to get a(0)..a(N)
    A:= Array(0..N):
    A[24]:= 1:
    for n from 25 to N do A[n]:= A[n-3] + A[n-25] mod 2 od:
    convert(A,list); # Robert Israel, Mar 25 2018
  • PARI
    A=matrix(N=25,N,i,j, if(i>1, i==j+1, setsearch([3,N],j)>0))*Mod(1, 2); a(n)=lift((A^(n-#A+1))[1,1]) \\ M. F. Hasler, Feb 17 2018

Formula

G.f. = x^24/(x^25+x^3+1), over GF(2). - M. F. Hasler, Feb 17 2018

A011743 A binary m-sequence: expansion of reciprocal of x^30 + x^16 + x^15 + x + 1 (mod 2, shifted by 29 initial 0's).

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0
Offset: 0

Views

Author

Keywords

Comments

Periodic with length of period 2^30-1. - M. F. Hasler, Feb 17 2018

References

  • S. W. Golomb, Shift-Register Sequences, Holden-Day, San Francisco, 1967.
  • H. D. Lueke, Korrelationssignale, Springer 1992, pp. 43-48.
  • F. J. MacWilliams and N. J. A. Sloane, The Theory of Error-Correcting Codes, Elsevier/North Holland, 1978, p. 408.

Crossrefs

Cf. A011655, A011656, ..., A011745 for other binary m-sequences, and A011746..A011751 for similar expansions over GF(2).

Programs

  • PARI
    A011743_vec=concat([1..29]*0, Vec(1/(x^30+x^16+x^15+x+1)+O(x^99))%2)
    A=matrix(30, 30, i, j, if(i>1, i==j+1, setsearch([1,15,16,30], j)>0))*Mod(1, 2);
    A011743(n)=lift((A^(n-29))[1, 1]) \\ M. F. Hasler, Feb 17 2018

A011731 A binary m-sequence: expansion of reciprocal of x^18 + x^7 + 1 (mod 2, shifted by 17 initial 0's).

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 1
Offset: 0

Views

Author

Keywords

Comments

Periodic with period of length 2^18 - 1 = 262143. - M. F. Hasler, Feb 17 2018

References

  • S. W. Golomb, Shift-Register Sequences, Holden-Day, San Francisco, 1967.
  • H. D. Lueke, Korrelationssignale, Springer 1992, pp. 43-48.
  • F. J. MacWilliams and N. J. A. Sloane, The Theory of Error-Correcting Codes, Elsevier/North Holland, 1978, p. 408.

Crossrefs

Cf. A011655, A011656, ..., A011745 for other binary m-sequences, and A011746..A011751 for similar expansions over GF(2).

Programs

  • PARI
    A=matrix(N=18,N,i,j,if(i>1,i==j+1,setsearch([7,N],j)>0))*Mod(1,2); a(n)=lift((A^(n-#A+1))[1,1]) \\ M. F. Hasler, Feb 17 2018

Formula

G.f. = x^17/(x^18 + x^7 + 1), over GF(2). - M. F. Hasler, Feb 17 2018

Extensions

Edited by M. F. Hasler, Feb 17 2018

A011732 A binary m-sequence: expansion of reciprocal of x^19 + x^6 + x^5 + x + 1 (mod 2, shifted by 18 initial 0's).

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 1, 0, 1, 0, 0, 1, 1, 0, 0, 0, 1, 1
Offset: 0

Views

Author

Keywords

Comments

Sequence is 2^19-1 = 524287-periodic. - M. F. Hasler, Feb 17 2018

References

  • S. W. Golomb, Shift-Register Sequences, Holden-Day, San Francisco, 1967.
  • H. D. Lueke, Korrelationssignale, Springer 1992, pp. 43-48.
  • F. J. MacWilliams and N. J. A. Sloane, The Theory of Error-Correcting Codes, Elsevier/North Holland, 1978, p. 408.

Crossrefs

Cf. A011655..A011745 for other binary m-sequences, and A011746..A011751 for similar expansions over GF(2).

Programs

  • PARI
    A=matrix(N=19,N,i,j, if(i>1, i==j+1, setsearch([1,5,6,N], j)>0))*Mod(1, 2); a(n)=lift((A^(n-#A+1))[1,1]) \\ M. F. Hasler, Feb 17 2018

Extensions

Edited by M. F. Hasler, Feb 17 2018

A011733 A binary m-sequence: expansion of reciprocal of x^20 + x^3 + 1 (mod 2, shifted by 19 initial 0's).

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1, 0, 0, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1, 0, 0, 0, 0
Offset: 0

Views

Author

Keywords

Comments

Sequence is 2^20-1 = 1048575-periodic. - M. F. Hasler, Feb 17 2018

References

  • S. W. Golomb, Shift-Register Sequences, Holden-Day, San Francisco, 1967.
  • H. D. Lueke, Korrelationssignale, Springer 1992, pp. 43-48.
  • F. J. MacWilliams and N. J. A. Sloane, The Theory of Error-Correcting Codes, Elsevier/North Holland, 1978, p. 408.

Crossrefs

Cf. A011655..A011745 for other binary m-sequences, and A011746..A011751 for similar expansions over GF(2).

Programs

  • PARI
    A=matrix(N=20,N,i,j, if(i>1, i==j+1, setsearch([3,N], j)>0))*Mod(1, 2); a(n)=lift((A^(n-#A+1))[1, 1]) \\ M. F. Hasler, Feb 17 2018

Extensions

Edited by M. F. Hasler, Feb 17 2018
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