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.

User: Gabriel Osorio

Gabriel Osorio's wiki page.

Gabriel Osorio has authored 2 sequences.

A319667 Palindromes a(n) = (10^n + 1)*(10^(n+1) + 1).

Original entry on oeis.org

22, 1111, 101101, 10011001, 1000110001, 100001100001, 10000011000001, 1000000110000001, 100000001100000001, 10000000011000000001, 1000000000110000000001, 100000000001100000000001, 10000000000011000000000001, 1000000000000110000000000001
Offset: 0

Author

Gabriel Osorio, Sep 25 2018

Keywords

Examples

			For n = 3: (10^3 + 1)(10^4 + 1) = 1001 * 10001 = 10011001, so a(3) = 10011001.
		

Programs

  • GAP
    a:=[22,1111,101101];; for n in [4..20] do a[n]:=111*a[n-1]-1110*a[n-2]+1000*a[n-3]; od; a; # Muniru A Asiru, Sep 26 2018
  • Maple
    seq((10^n+1)*(10^(n+1)+1),n=0..20); # Muniru A Asiru, Sep 26 2018
  • PARI
    a(n) = (10^n+1)*(10^(n+1)+1) \\ Felix Fröhlich, Sep 25 2018
    
  • PARI
    Vec(11*(2 - 121*x + 200*x^2) / ((1 - x)*(1 - 10*x)*(1 - 100*x)) + O(x^15)) \\ Colin Barker, Sep 25 2018
    

Formula

From Colin Barker, Sep 25 2018: (Start)
G.f.: 11*(2 - 121*x + 200*x^2) / ((1 - x)*(1 - 10*x)*(1 - 100*x)).
a(n) = 111*a(n-1) - 1110*a(n-2) + 1000*a(n-3) for n>2.
(End)

Extensions

More terms from Felix Fröhlich, Sep 25 2018

A269701 Cyclic Fibonacci sequence, restricted to maximum=6.

Original entry on oeis.org

0, 1, 1, 2, 3, 5, 2, 1, 3, 4, 1, 5, 6, 5, 5, 4, 3, 1, 4, 5, 3, 2, 5, 1, 6, 1, 1, 2, 3, 5, 2, 1, 3, 4, 1, 5, 6, 5, 5, 4, 3, 1, 4, 5, 3, 2, 5, 1, 6, 1, 1, 2, 3, 5, 2, 1, 3, 4, 1, 5, 6, 5, 5, 4, 3, 1, 4, 5, 3, 2, 5, 1, 6, 1, 1, 2, 3, 5, 2, 1, 3, 4, 1, 5, 6, 5, 5, 4, 3, 1, 4, 5, 3, 2, 5, 1, 6, 1
Offset: 0

Author

Gabriel Osorio, Mar 04 2016

Keywords

Comments

Sequence has a period of 24.

Examples

			For n = 6; F(5) + F(4) equals 8 then F(6) = 8 - 6 = 2.
		

Crossrefs

Cf. A000045 (Fibonacci numbers), A082117.

Programs

  • Erlang
    fibocy(1) -> 1;
    fibocy(2) -> 1;
    fibocy(N) when N > 1 ->
       Tmp = fibocy(N-1) + fibocy(N-2),
       if Tmp > 6 -> Tmp - 6;
          true -> Tmp
       end.
  • Maple
    A269701 := proc(n)
        option remember;
        if n <=5 then
            combinat[fibonacci](n) ;
        else
            a := procname(n-1)+procname(n-2) ;
            if a > 6 then
                a-6;
            else
                a;
            end if;
        end if;
    end proc: # R. J. Mathar, Apr 16 2016
  • Mathematica
    Table[Mod[Fibonacci[n], 6], {n, 100}] /. 0 -> 6 (* Alonso del Arte, Mar 28 2016 *)
    PadRight[{0},120,{6,1,1,2,3,5,2,1,3,4,1,5,6,5,5,4,3,1,4,5,3,2,5,1}] (* Harvey P. Dale, May 13 2019 *)

Formula

F(n) = F(n-1) + F(n-2) with F(0) = 0 and F(1) = 1 and F(n) = F(n-1) + F(n-2) - 6 if F(n-1) + F(n-2) > 6.
G.f.: ( -x *(1 +x +2*x^2 +3*x^3 +5*x^4 +2*x^5 +x^6 +3*x^7 +4*x^8 +x^9 +5*x^10 +6*x^11 +5*x^12 +5*x^13 +4*x^14 +3*x^15 +x^16 +4*x^17 +5*x^18 +3*x^19 +2*x^20 +5*x^21 +x^22 +6*x^23) ) / ( (x-1) *(1+x+x^2) *(1+x) *(1-x+x^2) *(1+x^2) *(x^4-x^2+1) *(1+x^4) *(x^8-x^4+1) ). - R. J. Mathar, Apr 16 2016