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.

A136189 The 3rd-order Zeckendorf array, T(n,k), read by antidiagonals.

Original entry on oeis.org

1, 2, 5, 3, 8, 7, 4, 12, 11, 10, 6, 17, 16, 15, 14, 9, 25, 23, 22, 21, 18, 13, 37, 34, 32, 31, 27, 20, 19, 54, 50, 47, 45, 40, 30, 24, 28, 79, 73, 69, 66, 58, 44, 36, 26, 41, 116, 107, 101, 97, 85, 64, 53, 39, 29, 60, 170, 157, 148, 142, 125, 94, 77, 57, 43, 33, 88, 249, 230
Offset: 1

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Author

Clark Kimberling, Dec 20 2007

Keywords

Comments

Rows satisfy this recurrence: T(n,k) = T(n,k-1) + T(n,k-3) for all k>=4.
Except for initial terms, (row 1) = A000930 (column 1) = A020942 (column 2) = A064105 (column 3) = A064106.
As a sequence, the array is a permutation of the natural numbers.
As an array, T is an interspersion (hence also a dispersion).

Examples

			Northwest corner:
  1  2  3  4  6  9  13  19 ...
  5  8 12 17 25 37  54  79 ...
  7 11 16 23 34 50  73 107 ...
 10 15 22 32 47 69 101 148 ...
 ...
		

Crossrefs

Formula

Row 1 is the 3rd-order Zeckendorf basis, given by initial terms b(1)=1, b(2)=2, b(3)=3 and recurrence b(k) = b(k-1) + b(k-3) for k>=4. Every positive integer has a unique 3-Zeckendorf representation: n = b(i(1)) + b(i(2)) + ... + b(i(p)), where |i(h)-i(j)| >= 3. Rows of T are defined inductively: T(n,1) is the least positive integer not in an earlier row. T(n,2) is obtained from T(n,1) as follows: if T(n,1) = b(i(1)) + b(i(2)) + ... + b(i(p)), then T(n,k+1) = b(i(1+k)) + b(i(2+k)) + ... + b(i(p+k)) for k=1,2,3,... .
A(n, k) = A000930(k)*A202342(n) + A000930(k-2)*A136495(n) + A000930(k-1)*(n-1) for n > 1. - Alan Michael Gómez Calderón, Dec 23 2024