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.

A240909 The sequency numbers of the 16 rows of a Hadamard-Walsh matrix of order 16.

Original entry on oeis.org

0, 15, 7, 8, 3, 12, 4, 11, 1, 14, 6, 9, 2, 13, 5, 10
Offset: 1

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Author

Ross Drewe, Apr 14 2014

Keywords

Comments

See A240908 for context. This sequence is the natural sequency ordering for an order 16 matrix.

Examples

			This is a fixed length sequence of only 16 values, as given.
		

Crossrefs

Cf. A240908 "natural order" sequencies for Hadamard-Walsh matrix, order 8.
Cf. A240910 "natural order" sequencies for Hadamard-Walsh matrix, order 32.
Cf. A153141 "dyadic order" sequencies for Hadamard-Walsh matrix, all orders.
Cf. A000975(n) is sequency of last row of H(n). - William P. Orrick, Jun 28 2015
Cf. A131271 (row 4, minus 1).

Formula

Recursion: H(2)=[1 1; 1 -1]; H(n) = H(n-1)*H(2), where * is Kronecker matrix product.
a(n) = A131271(4,n) - 1. - Mathew Englander, Jun 19 2021

Extensions

Definition of H(n) corrected by William P. Orrick, Jun 28 2015