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.

A166692 Triangle T(n,k) read by rows: T(n,k) = 2^(k-1), k>0, T(n,0) = (n+1) mod 2.

Original entry on oeis.org

1, 0, 1, 1, 1, 2, 0, 1, 2, 4, 1, 1, 2, 4, 8, 0, 1, 2, 4, 8, 16, 1, 1, 2, 4, 8, 16, 32, 0, 1, 2, 4, 8, 16, 32, 64, 1, 1, 2, 4, 8, 16, 32, 64, 128, 0, 1, 2, 4, 8, 16, 32, 64, 128, 256, 1, 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 0, 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024
Offset: 0

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Author

Paul Curtz, Oct 18 2009

Keywords

Comments

Variant of A166918.

Examples

			Triangle begins as:
  1;
  0, 1;
  1, 1, 2;
  0, 1, 2, 4;
  1, 1, 2, 4, 8;
  0, 1, 2, 4, 8, 16;
		

Crossrefs

Programs

  • Magma
    A166692:= func< n,k | k eq 0 select ((n+1) mod 2) else 2^(k-1) >;
    [A166692(n,k): k in [0..n], n in [0..15]]; // G. C. Greubel, Apr 24 2023
    
  • Mathematica
    Join[{1,0},Flatten[Riffle[Table[2^Range[0,n],{n,0,10}],{1,0}]]] (* Harvey P. Dale, Jan 18 2015 *)
  • SageMath
    def A166692(n,k): return ((n+1)%2) if (k==0) else 2^(k-1)
    flatten([[A166692(n,k) for k in range(n+1)] for n in range(16)]) # G. C. Greubel, Apr 24 2023

Formula

T(2n, k) = A011782(k).
T(2n+1, k) = A131577(k).
Sum_{k=0..n} T(n,k) = A051049(n).
From G. C. Greubel, Apr 24 2023: (Start)
T(2*n, n) = A011782(n).
Sum_{k=0..n} (-1)^k*T(n, k) = (-1)^n * A005578(n).
Sum_{k=0..n} T(n-k, k) = A106624(n). (End)

Extensions

More terms from Harvey P. Dale, Jan 18 2015