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.

Previous Showing 11-13 of 13 results.

A179252 Numbers that have 12 terms in their Zeckendorf representation.

Original entry on oeis.org

75024, 103681, 114627, 118808, 120405, 121015, 121248, 121337, 121371, 121384, 121389, 121391, 121392, 150049, 160995, 165176, 166773, 167383, 167616, 167705, 167739, 167752, 167757, 167759, 167760, 178706, 182887, 184484, 185094, 185327, 185416, 185450, 185463
Offset: 1

Views

Author

Emeric Deutsch, Jul 05 2010

Keywords

Examples

			75024 = 1 + 3 + 8 + 21 + 55 + 144 + 377 + 987 + 2584 + 6765 + 17711 + 46368;
103681 = 1 + 3 + 8 + 21 + 55 + 144 + 377 + 987 + 2584 + 6765 + 17711 + 75025.
		

Crossrefs

Programs

  • Maple
    with(combinat): B := proc (n) local A, ct, m, j: A := proc (n) local i: for i while fibonacci(i) <= n do n-fibonacci(i) end do end proc: ct := 0: m := n: for j while 0 < A(m) do ct := ct+1: m := A(m) end do: ct+1 end proc: Q := {}: for i from fibonacci(25)-1 to 180000 do if B(i) = 12 then Q := `union`(Q, {i}) else end if end do: Q;
  • Mathematica
    Reap[For[m = 0; k = 1, k <= 10^8, k++, If[BitAnd[k, 2 k] == 0, m++; If[DigitCount[k, 2, 1] == 12, Print[m]; Sow[m]]]]][[2, 1]] (* Jean-François Alcover, Aug 20 2023 *)

A135709 Not the sum of three distinct nonzero Fibonacci numbers.

Original entry on oeis.org

1, 2, 3, 4, 5, 7, 33, 46, 51, 53, 54, 67, 72, 74, 75, 80, 82, 83, 85, 86, 87, 88, 101, 106, 108, 109, 114, 116, 117, 119, 120, 121, 122, 127, 129, 130, 132, 133, 134, 135, 137, 138, 139, 140, 141, 142, 143, 156, 161, 163, 164, 169, 171, 172, 174, 175, 176, 177, 182, 184, 185
Offset: 1

Views

Author

N. J. A. Sloane, Mar 05 2008

Keywords

Crossrefs

Complement of A135558.

Programs

  • Maple
    # needs isA135558 from A135558
    A135709 := proc(n)
        option remember;
        local a;
        if n = 1 then
            1;
        else
            for a from procname(n-1)+1 do
                if not isA135558(a) then
                    return a;
                end if;
            end do:
        end if;
    end proc: # R. J. Mathar, Sep 09 2015
  • Mathematica
    With[{f=15},Complement[Range[Fibonacci[f]],Total/@Subsets[Fibonacci[ Range[ 2,f]],{3}]]] (* Harvey P. Dale, Sep 08 2019 *)

A111458 Numbers that cannot be represented as the sum of at most three Fibonacci numbers (with repetitions allowed).

Original entry on oeis.org

33, 46, 51, 53, 54, 67, 72, 74, 75, 80, 82, 83, 85, 86, 87, 88, 101, 106, 108, 109, 114, 116, 117, 119, 120, 121, 122, 127, 129, 130, 132, 133, 134, 135, 137, 138, 139, 140, 141, 142, 143, 156, 161, 163, 164, 169, 171, 172
Offset: 1

Views

Author

Stefan Steinerberger, Nov 15 2005

Keywords

Examples

			33 is neither a Fibonacci number nor can be written as the sum of two or three Fibonacci numbers.
		

Crossrefs

Programs

  • Maple
    isA111458 := proc(n) # returns true if n is in the sequence
        local xi,yi,x,y,z ;
        for xi from 0 do
            x := A000045(xi) ;
            if 3*x > n then
                return true;
            end if;
            for yi from xi do
                y := A000045(yi) ;
                if x+2*y > n then
                    break;
                else
                    z := n-x-y ;
                    if isA000045(z) then # see isFib in A000045
                        return false;
                    end if;
                end if;
            end do:
        end do:
    end proc:
    A111458 := proc(n)
        option remember;
        local a;
        if n = 0 then
            -1;
        else
            for a from procname(n-1)+1 do
                if isA111458(a) then
                    return a;
                end if;
            end do:
        end if;
    end proc: # R. J. Mathar, Sep 09 2015
  • Mathematica
    FibQ[n_] := IntegerQ[Sqrt[5n^2+4]] || IntegerQ[Sqrt[5n^2-4]];
    P[n_] := IntegerPartitions[n, 3, Select[Range[n], FibQ]];
    Select[Range[1000], P[#] == {}&] (* Jean-François Alcover, Jul 20 2023 *)
Previous Showing 11-13 of 13 results.