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.

A062877 0 and numbers representable as a sum of distinct odd-indexed Fibonacci numbers.

Original entry on oeis.org

0, 1, 2, 3, 5, 6, 7, 8, 13, 14, 15, 16, 18, 19, 20, 21, 34, 35, 36, 37, 39, 40, 41, 42, 47, 48, 49, 50, 52, 53, 54, 55, 89, 90, 91, 92, 94, 95, 96, 97, 102, 103, 104, 105, 107, 108, 109, 110, 123, 124, 125, 126, 128, 129, 130, 131, 136, 137, 138, 139, 141, 142, 143, 144
Offset: 0

Views

Author

Antti Karttunen, Jun 26 2001

Keywords

Examples

			F_1 = 1,
F_3 = 2,
F_1 + F_3 = 3,
F_5 = 5,
F_5 + F_1 = 6,
F_5 + F_3 = 7,
F_5 + F_3 + F_1 = 8,
F_7 = 13, ...
		

Crossrefs

A062878 gives the positions of A050614(n) in this sequence. A062879 is bisection.
A036796(n) - 1.
Cf. A022290 (even-indexed Fibonaccis), A054204.

Programs

  • Maple
    with(combinat); [seq(A062877(j),j=0..265)]; A062877 := n -> add((floor(n/(2^i)) mod 2)*fibonacci((2*i)+1),i=0..floor_log_2(n+1));
    floor_log_2 := proc(n) local nn,i; nn := n; for i from -1 to n do if(0 = nn) then RETURN(i); fi; nn := floor(nn/2); od; end;
    # alternative
    isA062877 := proc(n)
        local fset,fidx,ps ;
        if n = 0 then
            return true;
        end if;
        fset := {} ;
        for fidx from 1 by 2 do
            if combinat[fibonacci](fidx) >n then
                break;
            end if;
            fset := fset union {combinat[fibonacci](fidx)} ;
        end do:
        for ps in combinat[powerset](fset) do
            if n = add(fidx,fidx=ps) then
                return true;
            end if;
        end do:
        return false;
    end proc: # R. J. Mathar, Aug 22 2016
  • Mathematica
    Take[Union[Total/@Subsets[Fibonacci[Range[1,20,2]]]],70](* Harvey P. Dale, Dec 21 2013 *)
  • PARI
    my(m=Mod('x,'x^2-3*'x+1)); a(n) = subst(lift(subst(Pol(binary(n)), 'x,m)), 'x,2); \\ Kevin Ryde, Nov 25 2020