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 1-10 of 10 results.

A359574 Array read by antidiagonals: T(m,n) is the number of m X n binary arrays with all 1's connected and a path of 1's from top row to bottom row.

Original entry on oeis.org

1, 3, 1, 6, 7, 1, 10, 28, 17, 1, 15, 88, 144, 41, 1, 21, 245, 920, 730, 99, 1, 28, 639, 5191, 9362, 3692, 239, 1, 36, 1608, 27651, 104989, 94280, 18666, 577, 1, 45, 3968, 143342, 1111283, 2075271, 947760, 94384, 1393, 1, 55, 9689, 733512, 11457514, 42972329, 40792921, 9528128, 477264, 3363, 1
Offset: 1

Views

Author

Andrew Howroyd, Jan 06 2023

Keywords

Comments

The grid has m rows and n columns.

Examples

			Array begins:
================================================================
m\n| 1   2     3       4         5           6             7
---+------------------------------------------------------------
1  | 1   3     6      10        15          21            28 ...
2  | 1   7    28      88       245         639          1608 ...
3  | 1  17   144     920      5191       27651        143342 ...
4  | 1  41   730    9362    104989     1111283      11457514 ...
5  | 1  99  3692   94280   2075271    42972329     866126030 ...
6  | 1 239 18666  947760  40792921  1642690309   64270256276 ...
7  | 1 577 94384 9528128 801218515 62618577481 4741764527414 ...
  ...
		

Crossrefs

Formula

T(m,n) = A287151(m,n) - 2*A287151(m-1,n) + A287151(m-2,n) for m > 2.

A359575 Array read by antidiagonals: T(m,n) is the number of m X n binary arrays with a path of adjacent 1's from upper right corner to lower left corner.

Original entry on oeis.org

1, 1, 1, 1, 3, 1, 1, 8, 8, 1, 1, 20, 51, 20, 1, 1, 49, 295, 295, 49, 1, 1, 119, 1632, 3828, 1632, 119, 1, 1, 288, 8830, 46557, 46557, 8830, 288, 1, 1, 696, 47239, 546286, 1225194, 546286, 47239, 696, 1, 1, 1681, 251261, 6279393, 30754544, 30754544, 6279393, 251261, 1681, 1
Offset: 1

Views

Author

Andrew Howroyd, Jan 06 2023

Keywords

Examples

			Array begins:
================================================================
m\n| 1   2     3       4         5           6             7
---+------------------------------------------------------------
1  | 1   1     1       1         1           1             1 ...
2  | 1   3     8      20        49         119           288 ...
3  | 1   8    51     295      1632        8830         47239 ...
4  | 1  20   295    3828     46557      546286       6279393 ...
5  | 1  49  1632   46557   1225194    30754544     749866185 ...
6  | 1 119  8830  546286  30754544  1636193228   83949041929 ...
7  | 1 288 47239 6279393 749866185 83949041929 9009490924794 ...
  ...
		

Crossrefs

Main diagonal is A069343.
Rows 1..20 are A000012, A048739(n-1), A069325, A069326, A069327-A069342.

Formula

T(m,n) = T(n,m).

A163002 Number of n X n binary arrays with all 1s connected and a path of 1s from upper left corner to lower right corner.

Original entry on oeis.org

1, 3, 45, 2423, 482443, 360923899, 1012326365581, 10583931453268587, 410628432970492896401, 58940807698860767759080097, 31235684611422395105793077154373, 61025622782775877079925551890952450707, 439058030866550268551946597005515209497083151
Offset: 1

Views

Author

R. H. Hardin, Jul 20 2009

Keywords

Crossrefs

Main diagonal of A359573.

Extensions

a(8)-a(11) from Andrew Howroyd, Jan 06 2023
Terms a(12) and beyond from Andrew Howroyd, Jan 30 2023

A163003 Number of n X 3 binary arrays with all 1s connected and a path of 1s from upper left corner to lower right corner.

Original entry on oeis.org

1, 8, 45, 234, 1193, 6049, 30616, 154861, 783150, 3960215, 20025500, 101261654, 512042141, 2589202874, 13092613725, 66204360820, 334770228305, 1692805481383, 8559872259604, 43284012160451, 218870755473698, 1106746006355201, 5596392811360844, 28298825854292256
Offset: 1

Views

Author

R. H. Hardin, Jul 20 2009

Keywords

Crossrefs

Row 3 of A359573.

Formula

From R. J. Mathar, Aug 11 2009: (Start)
Empirical: a(n) = 8*a(n-1) -17*a(n-2) +10*a(n-3) +6*a(n-4) -14*a(n-5) +7*a(n-6) +6*a(n-7) -a(n-8).
Empirical g.f.: -x*(1+x)*(x^4-x^3+x^2+x-1)/ ((x^2+x-1)*(x^6-7*x^5+x^4+6*x^3-11*x^2+7*x-1)). (End)
The above empirical formulas are correct. - Andrew Howroyd, Jan 06 2023

A163004 Number of n X 4 binary arrays with all 1s connected and a path of 1s from upper left corner to lower right corner.

Original entry on oeis.org

1, 20, 234, 2423, 24455, 245972, 2473317, 24868730, 250043151, 2514035445, 25277060955, 254144975454, 2555267942068, 25691612225457, 258313003017344, 2597174783771339, 26112958991681036, 262549379235881855
Offset: 1

Views

Author

R. H. Hardin, Jul 20 2009

Keywords

Crossrefs

Row 4 of A359573.

A163005 Number of n X 5 binary arrays with all 1s connected and a path of 1s from upper left corner to lower right corner.

Original entry on oeis.org

1, 49, 1193, 24455, 482443, 9469361, 185899132, 3650755085, 71703384184, 1408344201283, 27661780849317, 543315030292163, 10671446719498293, 209601732562410408, 4116863153169917525, 80860792337380041052
Offset: 1

Views

Author

R. H. Hardin, Jul 20 2009

Keywords

Crossrefs

Row 5 of A359573.

A163006 Number of n X 6 binary arrays with all 1's connected and a path of 1's from upper left corner to lower right corner.

Original entry on oeis.org

1, 119, 6049, 245972, 9469361, 360923899, 13742823032, 523375860237, 19934900617863, 759343825445905, 28924772690242607, 1101801030283339240, 41969783540217156334, 1598712332667377324778, 60898124432179640663437, 2319730350681751316658034, 88363129835202482890093852
Offset: 1

Views

Author

R. H. Hardin, Jul 20 2009

Keywords

Crossrefs

Row 6 of A359573.

Extensions

Terms a(13) and beyond from Andrew Howroyd, Jan 06 2023

A163007 Number of n X 7 binary arrays with all 1s connected and a path of 1s from upper left corner to lower right corner.

Original entry on oeis.org

1, 288, 30616, 2473317, 185899132, 13742823032, 1012326365581, 74513820639189, 5483824484276487, 403566354707763962, 29699049493529506304, 2185591507222956126904, 160840358014084186505186, 11836434997659016450700108, 871057350099281882543862533
Offset: 1

Views

Author

R. H. Hardin, Jul 20 2009

Keywords

Crossrefs

Row 7 of A359573.

Extensions

Terms a(10) and beyond from Andrew Howroyd, Jan 06 2023

A163008 Number of n X 8 binary arrays with all 1s connected and a path of 1s from upper left corner to lower right corner.

Original entry on oeis.org

1, 696, 154861, 24868730, 3650755085, 523375860237, 74513820639189, 10583931453268587, 1502037917021311844, 213092418506218124956, 30227108359825419597288, 4287476337332745216533644, 608131459043610000423372550, 86256029502930854834545052267
Offset: 1

Views

Author

R. H. Hardin, Jul 20 2009

Keywords

Crossrefs

Row 8 of A359573.

Extensions

Terms a(8) and beyond from Andrew Howroyd, Jan 06 2023

A163009 Number of n X 9 binary arrays with all 1s connected and a path of 1s from upper left corner to lower right corner.

Original entry on oeis.org

1, 1681, 783150, 250043151, 71703384184, 19934900617863, 5483824484276487, 1502037917021311844, 410628432970492896401, 112160245091369049581311, 30623519350300448308681813, 8359714215859160247276696744, 2281871672070839340863159155338, 622836891043514813722341456961744
Offset: 1

Views

Author

R. H. Hardin, Jul 20 2009

Keywords

Crossrefs

Row 9 of A359573.

Extensions

Terms a(8) and beyond from Andrew Howroyd, Jan 06 2023
Showing 1-10 of 10 results.