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.

A134626 Sum-fill array starting with (1,2,4,8,16,...), powers of 2.

Original entry on oeis.org

1, 2, 1, 4, 3, 1, 8, 2, 4, 1, 16, 6, 3, 5, 1, 32, 4, 5, 4, 6, 1, 64, 12, 2, 7, 5, 7, 1, 128, 8, 8, 3, 9, 6, 8, 1, 256, 24, 6, 8, 4, 11, 7, 9, 1, 512, 16, 10, 2, 11, 5, 13, 8, 10, 1, 1024, 48, 16, 10, 7, 14, 6
Offset: 1

Views

Author

Clark Kimberling, Nov 04 2007

Keywords

Comments

(Row 2) is possibly A074323 except for an initial 1. The sequence represents the para-sequence in which the "final ordering" << is given by 1 << ... << 4 << 3 << 2. Row n contains 1,2,3,...2n, but not 2n+1. Row n starts like row n of A134625; e.g., row 6 of A123625 and row of A134626 have the same first 16 terms.

Examples

			Starting with x = row 3, Step 1 gives
y = (1,5,4,7,3,8,5,7,2,10,8,14,6,...).
Delete the second 5,7,8,... leaving row 4:
(1,5,4,7,3,8,2,10,14,6,...).
Northwest corner:
1 2 4 8 16 32
1 3 2 6 4 12
1 4 3 5 2 8
1 5 4 7 3 8
1 6 5 9 4 11.
		

References

  • C. Kimberling, Proper self-containing sequences, fractal sequences and para-sequences, preprint, 2007.

Crossrefs

Formula

Row 1 is A000079. Row n>=2 is produced from row n by the sum-fill operation, defined on an arbitrary infinite or finite sequence x = (x(1), x(2), x(3), ...) by the following two steps: Step 1. Form the sequence x(1), x(1)+x(2), x(2), x(2)+x(3), x(3), x(3)+x(4), ...; i.e., fill the space between x(n) and x(n+1) by their sum. Step 2. Delete duplicates; i.e., letting y be the sequence resulting from Step 1, if y(n+h)=y(n) for some h>=1, then delete y(n+h).

A134627 Sum-fill array starting with (1,2).

Original entry on oeis.org

1, 2, 1, 3, 2, 1, 4, 3, 5, 2, 1, 5, 4, 7, 3, 8, 2, 1, 6, 5, 9, 4, 11, 7, 10, 3, 8, 2, 1, 7, 6, 11, 5, 14, 9, 13, 4, 15, 18, 17, 10, 3, 8, 2, 1, 8, 7, 13, 6, 17, 11, 16, 5, 19, 14, 23, 9, 22, 4, 15, 33, 18, 35, 27, 10, 3, 2, 1, 9, 8, 15, 7, 20, 13, 19, 6, 23, 17, 28, 11, 27, 16, 21, 5, 24, 33
Offset: 1

Views

Author

Clark Kimberling, Nov 04 2007

Keywords

Comments

The sequence represents the para-sequence in which the "final ordering" << is given by 1 << ... << 4 << 3 << 2.

Examples

			The initial row (1,2) begets (1,3,2) because 3 = 1+2.
Then (1,3,2) begets (1,4,3,5,2) by sum-filling, etc.
First 5 rows:
1 2
1 3 2
1 4 3 5 2
1 5 4 7 3 8 2
1 6 5 9 4 1 7 10 3 8 2
		

References

  • Clark Kimberling, Proper self-containing sequences, fractal sequences and para-sequences, preprint, 2007.

Crossrefs

Formula

Row n>=2 is produced from row n by the sum-fill operation, defined on an arbitrary infinite or finite sequence x = (x(1), x(2), x(3), ...) by the following two steps: Step 1. Form the sequence x(1), x(1)+x(2), x(2), x(2)+x(3), x(3), x(3)+x(4), ...; i.e., fill the space between x(n) and x(n+1) by their sum. Step 2. Delete duplicates; i.e., letting y be the sequence resulting from Step 1, if y(n+h)=y(n) for some h>=1, then delete y(n+h).

A134628 Sum-fill array starting with (2,1).

Original entry on oeis.org

2, 1, 2, 3, 1, 2, 5, 3, 4, 1, 2, 7, 5, 8, 3, 4, 1, 2, 9, 7, 12, 5, 13, 8, 11, 3, 4, 1, 2, 11, 9, 16, 7, 19, 12, 17, 5, 18, 13, 21, 8, 14, 3, 4, 1, 2, 13, 11, 20, 9, 25, 16, 23, 7, 26, 19, 31, 12, 29, 17, 22, 5, 18, 34, 21, 8, 14, 3, 4, 1, 2, 15, 13, 24, 11, 31, 20, 29, 9, 34, 25, 41, 16, 39, 23
Offset: 1

Views

Author

Clark Kimberling, Nov 04 2007

Keywords

Comments

The sequence represents a para-sequence.

Examples

			The initial row (2,1) begets (2,3,1) because 3 = 2+1.
Then (2,3,1) begets (2,5,3,4,1) by sum-filling, etc.
First 5 rows:
2 1
2 3 1
2 5 3 4 1
2 7 5 8 3 4 1
1 6 5 9 4 1 7 10 3 8 2
		

References

  • Clark Kimberling, Proper self-containing sequences, fractal sequences and para-sequences, preprint, 2007.

Crossrefs

Formula

Row n>=2 is produced from row n by the sum-fill operation, defined on an arbitrary infinite or finite sequence x = (x(1), x(2), x(3), ...) by the following two steps: Step 1. Form the sequence x(1), x(1)+x(2), x(2), x(2)+x(3), x(3), x(3)+x(4), ...; i.e., fill the space between x(n) and x(n+1) by their sum. Step 2. Delete duplicates; i.e., letting y be the sequence resulting from Step 1, if y(n+h)=y(n) for some h>=1, then delete y(n+h).
Showing 1-3 of 3 results.