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.

A274883 Triangle read by rows, T(n,k) = 2^k*binomial(n,k)*A057977(n-k) for n>=0 and 0<=k<=n.

Original entry on oeis.org

1, 1, 2, 1, 4, 4, 3, 6, 12, 8, 2, 24, 24, 32, 16, 10, 20, 120, 80, 80, 32, 5, 120, 120, 480, 240, 192, 64, 35, 70, 840, 560, 1680, 672, 448, 128, 14, 560, 560, 4480, 2240, 5376, 1792, 1024, 256, 126, 252, 5040, 3360, 20160, 8064, 16128, 4608, 2304, 512
Offset: 0

Views

Author

Peter Luschny, Jul 14 2016

Keywords

Examples

			Triangle starts:
                       1;
                      1, 2;
                    1, 4, 4;
                  3, 6, 12, 8;
               2, 24, 24, 32, 16;
            10, 20, 120, 80, 80, 32;
         5, 120, 120, 480, 240, 192, 64;
     35, 70, 840, 560, 1680, 672, 448, 128;
14, 560, 560, 4480, 2240, 5376, 1792, 1024, 256;
		

Crossrefs

Cf. A000079 (T(n,n)), A057977 (T(n,0)), A077587 (row sum).
Cf. A189912. Row reversed A091894 is a subtriangle.

Programs

  • Maple
    T := (n,k) -> 2^k*binomial(n,k)*((n-k)!/floor((n-k)/2)!^2)/(floor((n-k)/2)+1);
    seq(seq(T(n,k), k=0..n), n=0..9);