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 1-8 of 8 results.

A269405 Number of length-n 0..4 arrays with no repeated value greater than or equal to the previous repeated value.

Original entry on oeis.org

5, 25, 120, 570, 2670, 12380, 56890, 259445, 1175355, 5293671, 23718780, 105781845, 469798125, 2078552055, 9164402118, 40277785365, 176503698495, 771372344695, 3362640467600, 14624384170213, 63463229049585, 274836205944615
Offset: 1

Views

Author

R. H. Hardin, Feb 25 2016

Keywords

Examples

			Some solutions for n=7:
..2. .1. .4. .2. .0. .1. .3. .1. .2. .0. .2. .3. .4. .4. .4. .0
..4. .0. .3. .1. .2. .4. .1. .0. .4. .2. .3. .2. .3. .2. .3. .0
..1. .3. .2. .3. .0. .4. .0. .4. .2. .0. .0. .0. .0. .3. .4. .2
..4. .4. .0. .1. .4. .1. .0. .0. .2. .0. .3. .2. .3. .1. .3. .3
..2. .2. .3. .2. .2. .2. .1. .2. .3. .4. .0. .3. .4. .4. .2. .4
..4. .2. .2. .4. .2. .0. .0. .3. .0. .2. .0. .1. .1. .3. .0. .2
..2. .1. .4. .4. .0. .4. .4. .2. .4. .0. .4. .0. .4. .4. .3. .0
		

Crossrefs

Column 4 of A269409

Formula

Empirical: a(n) = 20*a(n-1) - 150*a(n-2) + 460*a(n-3) - 65*a(n-4) - 2472*a(n-5) + 2320*a(n-6) + 6400*a(n-7) - 3840*a(n-8) - 10240*a(n-9) - 4096*a(n-10).
Empirical g.f.: x*(5 - 75*x + 370*x^2 - 380*x^3 - 1905*x^4 + 3265*x^5 + 5590*x^6 - 5865*x^7 - 11455*x^8 - 4339*x^9) / ((1 + x)^4*(1 - 4*x)^6). - Colin Barker, Jan 21 2019

A269406 Number of length-n 0..5 arrays with no repeated value greater than or equal to the previous repeated value.

Original entry on oeis.org

6, 36, 210, 1215, 6960, 39560, 223320, 1253190, 6995660, 38870136, 215074596, 1185563746, 6512894520, 35666937840, 194765568024, 1060744346079, 5762980508994, 31239002042780, 168977143019910, 912220049428041
Offset: 1

Views

Author

R. H. Hardin, Feb 25 2016

Keywords

Comments

Column 5 of A269409.

Examples

			Some solutions for n=6
..5. .0. .4. .3. .3. .1. .2. .4. .4. .1. .0. .0. .2. .2. .2. .0
..2. .5. .2. .1. .5. .3. .5. .4. .0. .5. .3. .1. .3. .4. .5. .4
..1. .0. .4. .5. .2. .0. .4. .2. .5. .2. .3. .5. .5. .1. .2. .2
..2. .5. .4. .2. .4. .3. .0. .0. .5. .5. .1. .2. .4. .4. .5. .4
..0. .4. .5. .0. .4. .5. .1. .0. .1. .4. .3. .1. .3. .5. .2. .5
..3. .1. .3. .3. .3. .1. .0. .5. .2. .1. .0. .0. .1. .3. .2. .1
		

Crossrefs

Cf. A269409.

Formula

Empirical: a(n) = 30*a(n-1) -360*a(n-2) +2090*a(n-3) -4905*a(n-4) -5076*a(n-5) +41160*a(n-6) -9900*a(n-7) -151875*a(n-8) -6250*a(n-9) +300000*a(n-10) +281250*a(n-11) +78125*a(n-12)

A269407 Number of length-n 0..6 arrays with no repeated value greater than or equal to the previous repeated value.

Original entry on oeis.org

7, 49, 336, 2289, 15477, 104006, 695135, 4623815, 30625210, 202067047, 1328649469, 8708852838, 56920021347, 371043659463, 2412849114074, 15655214564192, 101363364976160, 655024985471255, 4225174990367555, 27207648363845138
Offset: 1

Views

Author

R. H. Hardin, Feb 25 2016

Keywords

Comments

Column 6 of A269409.

Examples

			Some solutions for n=6
..4. .4. .5. .6. .4. .3. .6. .0. .6. .6. .3. .5. .5. .2. .1. .0
..6. .4. .3. .2. .0. .0. .4. .3. .0. .2. .6. .1. .1. .1. .6. .4
..5. .5. .1. .4. .1. .3. .6. .1. .3. .1. .1. .2. .5. .6. .5. .6
..1. .1. .0. .0. .1. .4. .2. .4. .2. .2. .3. .6. .5. .5. .1. .5
..6. .2. .6. .1. .5. .4. .1. .0. .6. .4. .3. .2. .2. .6. .0. .1
..5. .3. .4. .5. .2. .3. .6. .3. .5. .6. .5. .0. .6. .5. .4. .2
		

Crossrefs

Cf. A269409.

Formula

Empirical: a(n) = 42*a(n-1) -735*a(n-2) +6748*a(n-3) -32319*a(n-4) +53130*a(n-5) +172655*a(n-6) -705840*a(n-7) -418320*a(n-8) +3386880*a(n-9) +2522016*a(n-10) -7402752*a(n-11) -13063680*a(n-12) -7838208*a(n-13) -1679616*a(n-14)

A269408 Number of length-n 0..7 arrays with no repeated value greater than or equal to the previous repeated value.

Original entry on oeis.org

8, 64, 504, 3948, 30744, 238224, 1837752, 14121282, 108123624, 825227424, 6279994728, 47663522844, 360868232424, 2726022470928, 20549497120776, 154606709405835, 1161096042133440, 8705061811230400, 65160664171875440
Offset: 1

Views

Author

R. H. Hardin, Feb 25 2016

Keywords

Comments

Column 7 of A269409.

Examples

			Some solutions for n=5
..6. .0. .0. .4. .7. .2. .6. .3. .2. .6. .6. .4. .4. .3. .1. .5
..6. .1. .7. .7. .1. .1. .3. .4. .0. .2. .6. .7. .2. .0. .1. .2
..7. .7. .6. .4. .5. .6. .4. .2. .5. .5. .5. .1. .4. .6. .2. .4
..5. .7. .5. .4. .1. .2. .3. .3. .5. .2. .1. .6. .5. .1. .0. .0
..0. .3. .1. .7. .7. .4. .3. .1. .1. .7. .0. .3. .3. .1. .3. .0
		

Crossrefs

Cf. A269409.

Formula

Empirical: a(n) = 56*a(n-1) -1344*a(n-2) +17752*a(n-3) -135716*a(n-4) +545496*a(n-5) -463792*a(n-6) -4675336*a(n-7) +12240018*a(n-8) +21847336*a(n-9) -72913568*a(n-10) -123833976*a(n-11) +152002508*a(n-12) +520479176*a(n-13) +513890832*a(n-14) +230592040*a(n-15) +40353607*a(n-16)

A269410 Number of length-4 0..n arrays with no repeated value greater than or equal to the previous repeated value.

Original entry on oeis.org

9, 63, 222, 570, 1215, 2289, 3948, 6372, 9765, 14355, 20394, 28158, 37947, 50085, 64920, 82824, 104193, 129447, 159030, 193410, 233079, 278553, 330372, 389100, 455325, 529659, 612738, 705222, 807795, 921165, 1046064, 1183248, 1333497
Offset: 1

Views

Author

R. H. Hardin, Feb 25 2016

Keywords

Examples

			Some solutions for n=8:
..8. .3. .1. .0. .3. .0. .8. .2. .3. .1. .0. .4. .3. .5. .4. .6
..8. .8. .3. .5. .4. .2. .1. .4. .0. .5. .2. .4. .0. .6. .4. .8
..4. .7. .3. .8. .7. .2. .0. .5. .3. .3. .7. .0. .0. .1. .2. .0
..0. .8. .8. .7. .5. .8. .5. .8. .2. .8. .0. .0. .2. .1. .4. .2
		

Crossrefs

Row 4 of A269409.

Formula

Empirical: a(n) = n^4 + 4*n^3 + (7/2)*n^2 + (1/2)*n.
Conjectures from Colin Barker, Jan 21 2019: (Start)
G.f.: 3*x*(3 + 6*x - x^2) / (1 - x)^5.
a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5) for n>5.
(End)

A269411 Number of length-5 0..n arrays with no repeated value greater than or equal to the previous repeated value.

Original entry on oeis.org

12, 159, 804, 2670, 6960, 15477, 30744, 56124, 95940, 155595, 241692, 362154, 526344, 745185, 1031280, 1399032, 1864764, 2446839, 3165780, 4044390, 5107872, 6383949, 7902984, 9698100, 11805300, 14263587, 17115084, 20405154, 24182520
Offset: 1

Views

Author

R. H. Hardin, Feb 25 2016

Keywords

Examples

			Some solutions for n=8:
..0. .0. .2. .0. .2. .2. .6. .6. .3. .5. .8. .1. .5. .4. .2. .0
..5. .5. .8. .1. .3. .5. .0. .3. .8. .6. .7. .2. .0. .2. .3. .8
..8. .3. .6. .1. .0. .1. .5. .6. .7. .6. .0. .3. .5. .5. .0. .1
..4. .0. .7. .0. .2. .5. .0. .5. .1. .7. .7. .4. .7. .6. .7. .8
..5. .7. .0. .5. .3. .4. .4. .2. .7. .5. .8. .7. .7. .8. .8. .1
		

Crossrefs

Row 5 of A269409.

Formula

Empirical: a(n) = n^5 + 5*n^4 + (11/2)*n^3 + n^2 - (1/2)*n.
Conjectures from Colin Barker, Jan 21 2019: (Start)
G.f.: 3*x*(4 + 29*x + 10*x^2 - 3*x^3) / (1 - x)^6.
a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6) for n>6.
(End)

A269412 Number of length-6 0..n arrays with no repeated value greater than or equal to the previous repeated value.

Original entry on oeis.org

16, 394, 2872, 12380, 39560, 104006, 238224, 492312, 939360, 1681570, 2857096, 4647604, 7286552, 11068190, 16357280, 23599536, 33332784, 46198842, 62956120, 84492940, 111841576, 146193014, 188912432, 241555400, 305884800, 383888466
Offset: 1

Views

Author

R. H. Hardin, Feb 25 2016

Keywords

Examples

			Some solutions for n=6:
..3. .2. .5. .5. .1. .3. .3. .2. .5. .4. .1. .5. .0. .5. .2. .3
..5. .6. .2. .4. .0. .6. .6. .4. .1. .5. .6. .0. .3. .1. .0. .3
..4. .3. .6. .0. .4. .5. .3. .5. .0. .4. .1. .2. .2. .2. .6. .2
..5. .1. .4. .5. .1. .0. .4. .1. .0. .5. .0. .5. .6. .3. .2. .6
..3. .2. .5. .6. .4. .3. .5. .1. .5. .2. .4. .2. .2. .5. .0. .2
..1. .3. .4. .5. .1. .0. .0. .4. .1. .5. .3. .2. .5. .5. .3. .5
		

Crossrefs

Row 6 of A269409.

Formula

Empirical: a(n) = n^6 + 6*n^5 + 8*n^4 + (5/3)*n^3 - n^2 + (1/3)*n.
Conjectures from Colin Barker, Jan 21 2019: (Start)
G.f.: 2*x*(8 + 141*x + 225*x^2 - 5*x^3 - 9*x^4) / (1 - x)^7.
a(n) = 7*a(n-1) - 21*a(n-2) + 35*a(n-3) - 35*a(n-4) + 21*a(n-5) - 7*a(n-6) + a(n-7) for n>7.
(End)

A269413 Number of length-7 0..n arrays with no repeated value greater than or equal to the previous repeated value.

Original entry on oeis.org

20, 957, 10132, 56890, 223320, 695135, 1837752, 4302612, 9168780, 18124865, 33696300, 59523022, 100692592, 164133795, 259075760, 397577640, 595133892, 871360197, 1250765060, 1763612130, 2446878280, 3345312487, 4512600552
Offset: 1

Views

Author

R. H. Hardin, Feb 25 2016

Keywords

Examples

			Some solutions for n=4:
..2. .3. .1. .2. .4. .1. .4. .0. .2. .2. .0. .1. .0. .3. .4. .0
..2. .4. .2. .3. .4. .3. .1. .4. .3. .3. .3. .0. .2. .0. .4. .0
..1. .1. .1. .0. .3. .0. .2. .2. .4. .0. .3. .1. .3. .1. .1. .4
..2. .3. .3. .3. .3. .0. .4. .1. .4. .1. .2. .1. .2. .4. .4. .0
..3. .4. .4. .3. .0. .3. .0. .2. .2. .2. .0. .0. .0. .2. .0. .4
..1. .0. .1. .2. .2. .2. .2. .0. .4. .4. .3. .0. .2. .0. .4. .1
..0. .4. .1. .0. .4. .1. .1. .1. .1. .0. .0. .1. .4. .2. .3. .3
		

Crossrefs

Row 7 of A269409.

Formula

Empirical: a(n) = n^7 + 7*n^6 + 11*n^5 + (8/3)*n^4 - (11/6)*n^3 + (1/3)*n^2 - (1/6)*n.
Conjectures from Colin Barker, Jan 21 2019: (Start)
G.f.: x*(20 + 797*x + 3036*x^2 + 1510*x^3 - 296*x^4 - 27*x^5) / (1 - x)^8.
a(n) = 8*a(n-1) - 28*a(n-2) + 56*a(n-3) - 70*a(n-4) + 56*a(n-5) - 28*a(n-6) + 8*a(n-7) - a(n-8) for n>8.
(End)
Showing 1-8 of 8 results.