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.

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A100735 Inverse modulo 2 binomial transform of 2^n.

Original entry on oeis.org

1, 1, 3, 3, 15, 15, 45, 45, 255, 255, 765, 765, 3825, 3825, 11475, 11475, 65535, 65535, 196605, 196605, 983025, 983025, 2949075, 2949075, 16711425, 16711425, 50134275, 50134275, 250671375, 250671375, 752014125, 752014125, 4294967295, 4294967295
Offset: 0

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Author

Paul Barry, Dec 06 2004

Keywords

Comments

The modulo 2 binomial transform and its inverse are defined by
B(n) = Sum_{k=0..n} (binomial(n,k) mod 2)*A(k),
A(n) = Sum_{k=0..n} (-1)^A010060(n-k)*(binomial(n, k) mod 2)*B(k). - N. J. A. Sloane, Dec 20 2019
2^n may be retrieved as Sum_{k=0..n} mod(binomial(n,k),2)*a(k).

Crossrefs

Programs

  • Mathematica
    Table[Sum[(-1)^ThueMorse[n - k]*Mod[Binomial[n, k], 2]*2^k, {k, 0, n}], {n, 0, 50}] (* G. C. Greubel, Apr 17 2018 *)
  • PARI
    for(n=0,50, print1(abs(sum(k=0,n,(-1)^(hammingweight(k)%2)* lift(Mod(binomial(n,k),2))*2^k)), ", ")) \\ G. C. Greubel, Apr 17 2018

Formula

a(n) = Sum_{k=0..n} (-1)^A010060(n-k)*mod(binomial(n, k), 2)*2^k.
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