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.

Showing 1-1 of 1 results.

A143261 Triangle read by rows: binary reversed Gray code of binomial(n,m).

Original entry on oeis.org

1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 3, 5, 3, 1, 1, 7, 15, 15, 7, 1, 1, 5, 1, 15, 1, 5, 1, 1, 1, 31, 19, 19, 31, 1, 1, 1, 3, 9, 9, 83, 9, 9, 3, 1, 1, 11, 27, 63, 65, 65, 63, 27, 11, 1, 1, 15, 55, 17, 221, 65, 221, 17, 55, 15, 1, 1, 7, 13, 239, 495, 297, 297, 495, 239, 13, 7, 1
Offset: 0

Views

Author

Roger L. Bagula and Gary W. Adamson, Oct 21 2008

Keywords

Comments

Row sums are: 1, 2, 5, 4, 13, 46, 29, 104, 127, 334, 683, 2104,...

Examples

			1;
1, 1;
1, 3, 1;
1, 1, 1, 1;
1, 3, 5, 3, 1;
1, 7, 15, 15, 7, 1;
1, 5, 1, 15, 1, 5, 1;
1, 1, 31, 19, 19, 31, 1, 1;
1, 3, 9, 9, 83, 9, 9, 3, 1;
1, 11, 27, 63, 65, 65, 63, 27, 11, 1;
1, 15, 55, 17, 221, 65, 221, 17, 55, 15, 1;
1, 7, 13, 239, 495, 297, 297, 495, 239, 13, 7, 1;
		

Crossrefs

Programs

  • Maple
    A143261 := proc(n,m)
        binomial(n,m) ;
        A003188(%) ;
        A030101(%) ;
    end proc: # R. J. Mathar, Mar 10 2015
  • Mathematica
    GrayCodeList[k_] := Module[{b = IntegerDigits[k, 2], i}, Do[ If[b[[i - 1]] == 1, b[[i]] = 1 - b[[i]]], {i, Length[b], 2, -1} ]; b ]; b = Table[Table[Sum[GrayCodeList[Binomial[n, k]][[m + 1]]*2^m, {m, 0, Length[GrayCodeList[Binomial[n, k]]] - 1}], {k, 0, n}], {n, 0, Length[a]}]; Flatten[b]

Formula

T(n,m) = A030101(A003188(binomial(n,m))) = A030101(A143214(n,m)). - R. J. Mathar, Mar 10 2015

Extensions

Edited by R. J. Mathar, Mar 10 2015
Showing 1-1 of 1 results.