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.

A099888 XOR BINOMIAL transform of the powers of 3.

Original entry on oeis.org

1, 2, 8, 16, 80, 160, 640, 2784, 6560, 21824, 65280, 131072, 524800, 1056192, 4201728, 8408000, 43046720, 86135424, 361186816, 1467183104, 3443838080, 11367226112, 32550397696, 70111011712, 282403304960, 569106797952
Offset: 0

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Author

Paul D. Hanna, Oct 29 2004

Keywords

Comments

The diagonal of the XOR difference triangle A099887. The XOR BINOMIAL transform of this sequence returns the powers of 3. See A099884 for the definitions of the XOR BINOMIAL transform and the XOR difference triangle.

Crossrefs

Programs

  • PARI
    a(n)=local(B);B=0;for(i=0,n,B=bitxor(B,binomial(n,i)%2*3^(n-i)));B

Formula

a(n) = SumXOR_{k=0..n} (C(n, k) mod 2)*3^k, where SumXOR is summation under XOR.