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.

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A068723 Number of solenoidal flows (flow in = flow out) in a 4 X 4 square array with integer velocities -n .. n.

Original entry on oeis.org

1, 2053, 160403, 3096791, 28905785, 173429597, 773568107, 2789847759, 8576204625, 23279942261, 57201104003, 129540052071, 274074872265, 547436323149, 1040787422427, 1895867410719, 3326525754145, 5647051042021, 9308792104563, 14946774417783, 23438233878745, 35975222324029, 54153684727627, 80081666851567, 116509584233329
Offset: 0

Views

Author

R. H. Hardin, Feb 26 2002

Keywords

Examples

			Sample flows (. represents a space):
Numbers in long rows are on cell walls showing velocity rightward.
Numbers in long columns are on cell floors showing velocity downwards.
4 X 4 cell centers are at the intersection of long rows and long columns.
n=1:
.. 0 . 0 . 0 . 0
.0. -1. -1. -1 . 0
.. 1 . 0 . 0. -1
.0 . 0. -1 . 0 . 0
.. 1 . 1. -1. -1
.0 . 0 . 1 . 0 . 0
.. 1 . 0 . 0. -1
.0 . 1 . 1 . 1 . 0
.. 0 . 0 . 0 . 0
n=2:
.. 0 . 0 . 0 . 0
.0. -2. -1. -2 . 0
.. 2. -1 . 1. -2
.0 . 0. -2 . 0 . 0
.. 2 . 1. -1. -2
.0 . 0 . 1 . 0 . 0
.. 2 . 0 . 0. -2
.0 . 2 . 2 . 2 . 0
.. 0 . 0 . 0 . 0
		

Crossrefs

Cf. A005408 (2 X 2), A068722 (3 X 3), A068724 (5 X 5), A068725 (6 X 6).
By velocity limit 1..13 A068726-A068738.

Formula

Empirical G.f.: (x+1) * (x^8 + 2042*x^7 + 137876*x^6 + 1447150*x^5 + 3462710*x^4 + 1447150*x^3 + 137876*x^2 + 2042*x + 1) / (x-1)^10. [Colin Barker, Jul 31 2012]

Extensions

a(14)-a(24) from Sean A. Irvine, Mar 06 2024

A068724 Number of solenoidal flows (flow in = flow out) in a 5 X 5 square array with integer velocities -n .. n.

Original entry on oeis.org

1, 569397, 1305759171, 251611610655, 13336307324915, 322309309862183, 4598900066440609, 44976296745414509, 331136639667811845, 1954290045098180729, 9661874271897648847, 41320247284448146619, 156588834507399529975
Offset: 0

Views

Author

R. H. Hardin, Feb 26 2002

Keywords

Examples

			Sample flows (. represents a space):
Numbers in long rows are on cell walls showing velocity rightward.
Numbers in long columns are on cell floors showing velocity downwards.
5 X 5 cell centers are at the intersection of long rows and long columns.
n=1:
.. 0 . 0 . 0 . 0 . 0
.0. -1. -1. -1. -1 . 0
.. 1 . 0 . 0 . 0. -1
.0 . 0. -1. -1 . 0 . 0
.. 1 . 1 . 0. -1. -1
.0 . 0 . 0 . 0 . 0 . 0
.. 1 . 1 . 0. -1. -1
.0 . 0 . 1 . 1 . 0 . 0
.. 1 . 0 . 0 . 0. -1
.0 . 1 . 1 . 1 . 1 . 0
.. 0 . 0 . 0 . 0 . 0
n=2:
.. 0 . 0 . 0 . 0 . 0
.0. -2. -1. -1. -1 . 0
.. 2. -1 . 0 . 0. -1
.0 . 0. -2. -2. -1 . 0
.. 2 . 1 . 0. -1. -2
.0 . 0. -1. -1 . 0 . 0
.. 2 . 2 . 0. -2. -2
.0 . 0 . 2 . 2 . 0 . 0
.. 2 . 0 . 0 . 0. -2
.0 . 2 . 2 . 2 . 2 . 0
.. 0 . 0 . 0 . 0 . 0
		

Crossrefs

Cf. 2 X 2=1, 3, 5, 7..., 3 X 3 A068722, 4 X 4 A068723, 6x6 A068725, by velocity limit 1..13 A068726-A068738.

Extensions

a(6)-a(12) from Sean A. Irvine, Mar 06 2024

A068752 Number of potential flows in n X n array with integer velocities in -5..5, i.e., number of n X n arrays with adjacent elements differing by no more than 5, counting arrays differing by a constant only once.

Original entry on oeis.org

1, 891, 45642289, 138190481342321, 24953087551680958151267
Offset: 1

Views

Author

R. H. Hardin, Feb 27 2002

Keywords

Crossrefs

By size 3 X 3, ..., 6 X 6 A068744-A068747, by velocity limit 1..14 A068248-A068761, A068752 solenoidal flows A068722-A068738.

A068727 Number of solenoidal flows (flow in = flow out) in an n X n square array with integer velocities in -2 .. 2.

Original entry on oeis.org

1, 5, 247, 160403, 1305759171, 134771061592765, 176541437214450498265, 2940055615889904390546839103, 623112842926151670996790416231139397
Offset: 1

Views

Author

R. H. Hardin, Feb 26 2002

Keywords

Crossrefs

By size 3 X 3, ..., 6 X 6 A068722-A068725, by velocity limit 1..13 A068726-A068738.

Extensions

a(9) from Sean A. Irvine, Mar 08 2024

A068728 Number of solenoidal flows (flow in = flow out) in an n X n square array with integer velocities in -3 .. 3.

Original entry on oeis.org

1, 7, 925, 3096791, 251611610655, 500885416261650533, 24461989414349531084868443, 29358790904767905695470325002387331
Offset: 1

Views

Author

R. H. Hardin, Feb 26 2002

Keywords

Crossrefs

By size 3 X 3, ..., 6 X 6 A068722-A068725, by velocity limit 1..13 A068726-A068738.

Extensions

a(7)-a(8) from Sean A. Irvine, Mar 07 2024

A068729 Number of solenoidal flows (flow in = flow out) in an n X n square array with integer velocities in -4 .. 4.

Original entry on oeis.org

1, 9, 2501, 28905785, 13336307324915, 247753867499441888279, 185592614324336736251073584343
Offset: 1

Views

Author

R. H. Hardin, Feb 26 2002

Keywords

Crossrefs

By size 3 X 3, ..., 6 X 6 A068722-A068725, by velocity limit 1..13 A068726-A068738.

Extensions

a(6)-a(7) from Sean A. Irvine, Mar 08 2024

A068730 Number of solenoidal flows (flow in = flow out) in an n X n square array with integer velocities in -5 .. 5.

Original entry on oeis.org

1, 11, 5551, 173429597, 322309309862183, 35922392489639958547367
Offset: 1

Views

Author

R. H. Hardin, Feb 26 2002

Keywords

Crossrefs

By size 3 X 3, ..., 6 X 6 A068722-A068725, by velocity limit 1..13 A068726-A068738.

Extensions

a(6) from Sean A. Irvine, Mar 11 2024

A068731 Number of solenoidal flows (flow in = flow out) in an n X n square array with integer velocities in -6 .. 6.

Original entry on oeis.org

1, 13, 10795, 773568107, 4598900066440609, 2286173927365217148894607
Offset: 1

Views

Author

R. H. Hardin, Feb 26 2002

Keywords

Crossrefs

By size 3 X 3, ..., 6 X 6 A068722-A068725, by velocity limit 1..13 A068726-A068738.

Extensions

a(5)-a(6) from Sean A. Irvine, Mar 08 2024

A068732 Number of solenoidal flows (flow in = flow out) in an n X n square array with integer velocities in -7 .. 7.

Original entry on oeis.org

1, 15, 19097, 2789847759, 44976296745414509, 80633423581611695455020595
Offset: 1

Views

Author

R. H. Hardin, Feb 26 2002

Keywords

Crossrefs

By size 3 X 3, ..., 6 X 6 A068722-A068725, by velocity limit 1..13 A068726-A068738.

Extensions

a(5)-a(6) from Sean A. Irvine, Mar 09 2024

A068733 Number of solenoidal flows (flow in = flow out) in an n X n square array with integer velocities in -8 .. 8.

Original entry on oeis.org

1, 17, 31465, 8576204625, 331136639667811845
Offset: 1

Views

Author

R. H. Hardin, Feb 26 2002

Keywords

Crossrefs

By size 3 X 3, ..., 6 X 6 A068722-A068725, by velocity limit 1..13 A068726-A068738.

Extensions

a(5) from Sean A. Irvine, Mar 11 2024
Previous Showing 11-20 of 35 results. Next