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.

A000383 Hexanacci numbers with a(0) = ... = a(5) = 1.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 6, 11, 21, 41, 81, 161, 321, 636, 1261, 2501, 4961, 9841, 19521, 38721, 76806, 152351, 302201, 599441, 1189041, 2358561, 4678401, 9279996, 18407641, 36513081, 72426721, 143664401, 284970241, 565262081, 1121244166, 2224080691, 4411648301
Offset: 0

Views

Author

Keywords

References

  • N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Cf. A060455.
Cf. A001592 (Hexanacci numbers with a(0) = ... = a(4) = 0 and a(5)=1).
Cf. A247192 (indices of primes in this sequence).
Cf. A249413 (primes in this sequence).

Programs

  • Maple
    A000383:=(-1+z**2+2*z**3+3*z**4+4*z**5)/(-1+z**2+z**3+z**4+z**5+z+z**6); # Simon Plouffe in his 1992 dissertation
    a:= n-> (Matrix([[1$6]]). Matrix(6, (i,j)-> if (i=j-1) or j=1 then 1 else 0 fi)^n)[1,6]: seq(a(n), n=0..28); # Alois P. Heinz, Aug 26 2008
  • Mathematica
    LinearRecurrence[{1,1,1,1,1,1},{1,1,1,1,1,1},50] (* Harvey P. Dale, Oct 30 2013 *)
  • PARI
    a(n)=([0,1,0,0,0,0; 0,0,1,0,0,0; 0,0,0,1,0,0; 0,0,0,0,1,0; 0,0,0,0,0,1; 1,1,1,1,1,1]^n*[1;1;1;1;1;1])[1,1] \\ Charles R Greathouse IV, Sep 24 2015

Formula

G.f. ( -1+x^2+2*x^3+3*x^4+4*x^5 ) / ( -1+x+x^2+x^3+x^4+x^5+x^6 ). - R. J. Mathar, Oct 11 2011