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.

Showing 1-3 of 3 results.

A181661 Upper Beatty array of the golden ratio, (1+sqrt(5))/2.

Original entry on oeis.org

1, 2, 2, 6, 5, 3, 23, 17, 7, 4, 95, 68, 24, 10, 5, 400, 284, 95, 35, 13, 6, 1692, 1199, 396, 141, 46, 15, 7, 7165, 5075, 1671, 590, 186, 53, 18, 8, 30349, 21494, 7072, 2492, 778, 214, 64, 20, 9, 128558, 91046, 29951, 10549, 3286, 896, 259, 71, 23, 10, 544578
Offset: 1

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Author

Clark Kimberling, Nov 18 2010

Keywords

Comments

(row 1)=-1+A049652.
(column 1)=A000027.
(column 2)=A001950=(u(n)), or simply u.
(column 3)=u(u(n))+l(l(n)), or simply uu+ll.
(column 4)=u(uu+ll)+l(ul+lu),
whereas Column 4 of the lower Beatty array
is u(ul+lu)+l(uu+ll).
U(n,k)-L(n,k)=n for n>=1, k>=0.

Examples

			Northwest corner of the array:
  1     2     6    23    95    400 ...
  2     5    17    68   284   1199 ...
  3     7    24    95   396   1671 ...
  4    10    35   141   590   2492 ...
		

Crossrefs

Formula

Here we introduce Beatty arrays. Suppose that
(u(1),u(2),...) and (l(1),l(2),...) are the Beatty
sequences of positive real numbers r and s=r/(1-r), where
r=1, let
U(n,0)=n, U(n,1)=u(1), L(n,0)=0, L(n,1)=l(1),
and for k>=2 let x=floor(r*u(k-1)), y=floor(r*l(k-1)),
a=x+u(k-1), b=x, c=y+l(k-1), d=y,
U(n,k)=a+d, L(n,k)=b+c. We call U and L the upper and
lower Beatty arrays of r (and of s). Note that
U(n,k)-L(n,k)=U(n,1)-L(n,1) for all n>=1 and k>=1.

A182638 Upper Beatty array of sqrt(2).

Original entry on oeis.org

1, 3, 2, 8, 6, 3, 27, 16, 10, 4, 100, 54, 29, 13, 5, 379, 200, 102, 38, 17, 6, 1447, 759, 381, 133, 50, 20, 7, 5536, 2899, 1449, 497, 176, 59, 23, 8, 21191, 11092, 5538, 1890, 658, 208, 67, 27, 9, 81124, 42458, 21192, 7223, 2504, 779, 235, 80
Offset: 1

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Author

Clark Kimberling, Nov 22 2010

Keywords

Comments

Upper and lower Beatty arrays U and L are defined in general at A181661. Notation: U(n,k) and L(n,k) for n>=1 and k>=0.
Column 2 of U is A001952, the Beatty sequence of 2+sqrt(2); column 2 of L is the complement, A001951, the Beatty sequence of sqrt(2).
U(n,k)-L(n,k)=2n for all n>=1 and k>=1.

Examples

			Northwest corner of U:
1.....3.....8....27...100...
2.....6....16....54...200...
3....10....29...102...381...
4....13....38...133...497...
		

Crossrefs

A182639 Lower Beatty array of sqrt(2).

Original entry on oeis.org

0, 1, 0, 6, 2, 0, 25, 12, 4, 0, 98, 50, 23, 5, 0, 377, 196, 96, 30, 7, 0, 1445, 755, 375, 125, 40, 8, 0, 5534, 2895, 1443, 489, 166, 479, 0, 21189, 11088, 5532, 1882, 648, 196, 53, 11, 0, 81122, 42454, 21186, 7215, 2494, 767, 221, 64, 12, 0, 310571
Offset: 1

Views

Author

Clark Kimberling, Nov 22 2010

Keywords

Comments

Upper and lower Beatty arrays U and L are defined in general at A181661. Notation: U(n,k) and L(n,k) for n>=1 and k>=0.

Examples

			Northwest corner of L:
0...1....6...25....98...
0...2...12...50...196...
0...4...23...96...375...
0...5...30..125...489...
		

Crossrefs

Showing 1-3 of 3 results.