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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A133094 A007318 * A133080 * A097806, as infinite lower triangular matrices.

Original entry on oeis.org

1, 3, 1, 5, 3, 1, 7, 7, 5, 1, 9, 14, 14, 5, 1, 11, 25, 30, 16, 7, 1, 13, 41, 55, 41, 27, 7, 1, 15, 63, 91, 91, 77, 29, 9, 1, 17, 92, 140, 182, 182, 92, 44, 9, 1, 19, 129, 204, 336, 378, 246, 156, 46, 11, 1
Offset: 1

Views

Author

Gary W. Adamson, Sep 09 2007

Keywords

Comments

Row sums give A133095.
Binomial transform of an infinite lower triangular matrix with (1,1,1,...) in the main diagonal, (2,1,2,1,...) in the subdiagonal and (0,1,0,1,...) in the subsubdiagonal.

Examples

			First few rows of the triangle:
   1;
   3,  1;
   5,  3,  1;
   7,  7,  5,  1;
   9, 14, 14,  5,  1;
  11, 25, 30, 16,  7,  1;
  13, 41, 55, 41, 27,  7,  1;
  ...
		

Crossrefs

A179744 a(0) = 1, a(n) = 3*2^(n-1) - n for n>0.

Original entry on oeis.org

1, 2, 4, 9, 20, 43, 90, 185, 376, 759, 1526, 3061, 6132, 12275, 24562, 49137, 98288, 196591, 393198, 786413, 1572844, 3145707, 6291434, 12582889, 25165800, 50331623, 100663270, 201326565, 402653156, 805306339, 1610612706, 3221225441
Offset: 0

Views

Author

Gary W. Adamson, Jul 25 2010

Keywords

Comments

Equals row sums of triangle A179743.
Essentially the same as A133095 and A123720. - R. J. Mathar, Jul 26 2010

Examples

			a(5) = 43 = 2*a(4) + 3 = 2*20 + 3
a(5) = 43 = sum of row 5 terms, triangle A179743: (1 + 5 + 8 + 12 + 16 + 1).
		

Crossrefs

Cf. A179743.

Programs

Formula

a(0) = 1, a(1) = 2; a(n) = 2*a(n-1) + (n-2) for n>1.
G.f. 1-x*(2-4*x+3*x^2) / ( (2*x-1)*(x-1)^2 ). - R. J. Mathar, May 03 2013

Extensions

More terms from Robert G. Wilson v, Aug 03 2010
Showing 1-2 of 2 results.