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.

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

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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