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.

A212362 Triangle by rows, binomial transform of the beheaded Pascal's triangle A074909.

Original entry on oeis.org

1, 2, 2, 4, 7, 3, 8, 19, 15, 4, 16, 47, 52, 26, 5, 32, 111, 155, 110, 40, 6, 64, 255, 426, 385, 200, 57, 7, 128, 575, 1113, 1211, 805, 329, 77, 8, 256, 1279, 2808, 3556, 2856, 1498, 504, 100, 9, 512, 2815, 6903, 9948, 9324, 5922, 2562, 732, 126, 10
Offset: 0

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Author

Gary W. Adamson, Jun 29 2012

Keywords

Comments

Row sums of the triangle inverse = A027641/A027642, the Bernoulli numbers; (1, -1/2, 1/6, 0, -1/30,...)

Examples

			First few rows of the triangle are:
    1;
    2,    2;
    4,    7,    3;
    8,   19,   15,    4
   16,   47,   52,   26,    5;
   32,  111,  155,  110,   40,    6;
   64,  255,  426,  385,  200,   57,   7;
  128,  575, 1113, 1211,  805,  329,  77,   8;
  256, 1279, 2808, 3556, 2856, 1498, 504, 100, 9;
  ...
		

Crossrefs

Cf. A074909, A027641/A027642, A027649 (row sums), A006589 (2nd column), A106515.

Programs

  • Magma
    A074909:= func< n,k | k lt 0 or k gt n select 0 else Binomial(n+1, k) >;
    A212362:= func< n,k | (&+[ Binomial(n,j)*A074909(j, k) : j in [0..n]]) >;
    [A212362(n,k): k in [0..n], n in [0..12]]; // G. C. Greubel, Aug 05 2021
    
  • Maple
    A212362 := proc(n,k)
            add( binomial(n,i)*A074909(i,k),i=0..n) ;
    end proc: # R. J. Mathar, Aug 03 2015
  • Mathematica
    T[n_, k_]= 2^(n-k)*Binomial[n+1, k] + (2^(n-k) -1)*Binomial[n, k-1];
    Table[T[n, k] , {n,0,12}, {k,0,n}] //Flatten (* G. C. Greubel, Aug 05 2021 *)
  • Sage
    def T(n, k): return 2^(n-k)*binomial(n+1, k) + (2^(n-k) - 1)*binomial(n, k-1)
    flatten([[T(n,k) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Aug 05 2021

Formula

Binomial transform of the beheaded Pascal's triangle (A074909) as a matrix. (The beheaded Pascal matrix deletes the rightmost border of 1's.)
From G. C. Greubel, Aug 05 2021: (Start)
T(n, k) = Sum_{j=0..n} binomial(n, j)*binomial(j+1, k) - binomial(n, k-1), with T(n, 0) = 2^n.
T(n, k) = 2^(n-k)*binomial(n+1, k) + (2^(n-k) - 1)*binomial(n, k-1).
Sum_{k=0..n} T(n, k) = A027649(n).
Sum_{k=0..floor(n/2)} T(n-k, k) = A106515(n). (End)

Extensions

a(22) corrected by G. C. Greubel, Aug 05 2021