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.

A173475 Triangle T(n, k) = c(n)/(c(k)*c(n-k)) where c(n) = Product_{j=0..n} A051179(j), read by rows.

Original entry on oeis.org

1, 1, 1, 1, 5, 1, 1, 85, 85, 1, 1, 21845, 371365, 21845, 1, 1, 1431655765, 6254904037285, 6254904037285, 1431655765, 1, 1, 6148914691236517205, 1760625833240390967011987365, 452480839142780478522080752805, 1760625833240390967011987365, 6148914691236517205, 1
Offset: 0

Views

Author

Roger L. Bagula, Feb 19 2010

Keywords

Examples

			Triangle begins as:
  1;
  1,          1;
  1,          5,             1;
  1,         85,            85,             1;
  1,      21845,        371365,         21845,          1;
  1, 1431655765, 6254904037285, 6254904037285, 1431655765, 1;
		

Crossrefs

Cf. A051179.

Programs

  • Mathematica
    c[n_]:= Product[2^(2^j) - 1, {j,0,n}];
    T[n_, k_]:= c[n]/(c[k]*c[n-k]);
    Table[T[n, k], {n,0,8}, {k,0,n}]//Flatten
  • Sage
    @CachedFunction
    def c(n): return product( 2^(2^j) -1 for j in (0..n) )
    def T(n,k): return c(n)/(c(k)*c(n-k))
    flatten([[T(n,k) for k in (0..n)] for n in (0..8)]) # G. C. Greubel, Apr 26 2021

Formula

T(n, k) = c(n)/(c(k)*c(n-k)) where c(n) = Product_{j,0,n} A051179(j).

Extensions

Edited by G. C. Greubel, Apr 26 2021