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.

A022415 Kim-sums: "Kimberling sums" K_n + K_4.

Original entry on oeis.org

3, 10, 13, 15, 18, 21, 23, 26, 28, 31, 34, 36, 39, 42, 44, 47, 49, 52, 55, 57, 60, 62, 65, 68, 70, 73, 76, 78, 81, 83, 86, 89, 91, 94, 97, 99, 102, 104, 107, 110, 112, 115, 117, 120, 123, 125, 128, 131, 133, 136, 138, 141, 144, 146, 149, 151, 154, 157, 159, 162, 165, 167, 170, 172, 175, 178
Offset: 0

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Keywords

References

  • Posting to math-fun mailing list Jan 10 1997.

Crossrefs

The "Kim-sums" K_n + K_i for i = 2 through 12 are given in A022413, A022414, A022415, A022416, ..., A022423.

Programs

  • Maple
    Ki := proc(n,i)
        option remember;
        local phi ;
        phi := (1+sqrt(5))/2 ;
        if i= 0 then
            n;
        elif i=1 then
            floor((n+1)*phi) ;
        else
            procname(n,i-1)+procname(n,i-2) ;
        end if;
    end proc:
    Kisum := proc(n,m)
        local ks,a,i;
        ks := [seq( Ki(n,i)+Ki(m,i),i=0..5)] ;
        for i from 0 to 2 do
            for a from 0 do
                if Ki(a,0) = ks[i+1] and Ki(a,1) = ks[i+2] then
                    return a;
                end if;
                if Ki(a,0) > ks[i+1] then
                    break;
                end if;
            end do:
        end do:
    end proc:
    A022415 := proc(n)
        if n = 0 then
            3;
        else
            Kisum(n-1,3) ;
        end if;
    end proc:
    seq(A022415(n),n=0..80) ; # R. J. Mathar, Sep 03 2016
  • Mathematica
    Ki[n_, i_] := Ki[n, i] = Which[i == 0, n, i == 1, Floor[(n + 1)* GoldenRatio], True, Ki[n, i - 1] + Ki[n, i - 2]];
    Kisum[n_, m_] := Module[{ks, a, i}, ks = Table[Ki[n, i] + Ki[m, i], {i, 0, 5}]; For[i = 0, i <= 2, i++, For[a = 0, True, a++, If[Ki[a, 0] == ks[[i + 1]] && Ki[a, 1] == ks[[i + 2]], Return@a]; If[Ki[a, 0] > ks[[i + 1]], Break[]]]]];
    a[n_] := If[n == 0, 3, Kisum[n - 1, 3]];
    Table[a[n], {n, 0, 80}] (* Jean-François Alcover, Oct 15 2023, after R. J. Mathar *)