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.

A250357 Number of length n arrays x(i), i=1..n with x(i) in i..i+4 and no value appearing more than 3 times.

Original entry on oeis.org

5, 25, 125, 623, 3094, 15365, 76300, 378880, 1881364, 9342081, 46388915, 230348138, 1143813376, 5679703079, 28203050974, 140044659409, 695403722139, 3453086599482, 17146596550508, 85142890221146, 422784296221329
Offset: 1

Views

Author

R. H. Hardin, Nov 19 2014

Keywords

Examples

			Some solutions for n=6:
..2....4....0....0....2....2....0....2....0....1....3....3....4....1....2....0
..4....3....4....2....2....3....2....3....4....1....2....1....4....1....5....3
..2....5....5....5....6....6....4....6....3....2....2....5....5....5....6....6
..4....6....7....6....3....5....5....4....7....4....4....7....4....4....7....3
..8....7....4....5....5....8....6....4....7....7....5....6....6....8....6....8
..7....9....9....6....5....7....7....8....6....5....5....7....6....5....8....9
		

Crossrefs

Column 4 of A250361.

Formula

Empirical: a(n) = 5*a(n-1) - 2*a(n-4) - 11*a(n-5) + a(n-8).
Empirical g.f.: x*(5 - 2*x^3 - 11*x^4 + x^7) / (1 - 5*x + 2*x^4 + 11*x^5 - x^8). - Colin Barker, Nov 13 2018

A250358 Number of length n arrays x(i), i=1..n with x(i) in i..i+5 and no value appearing more than 3 times.

Original entry on oeis.org

6, 36, 216, 1293, 7712, 45866, 272760, 1621963, 9644496, 57346376, 340979312, 2027446948, 12055094608, 71678940042, 426199029864, 2534155836542, 15067950109140, 89593195408640, 532716168060704, 3167500770096043
Offset: 1

Views

Author

R. H. Hardin, Nov 19 2014

Keywords

Comments

Column 5 of A250361

Examples

			Some solutions for n=6
..4....5....2....0....1....1....3....0....1....4....2....0....2....3....1....3
..1....2....6....1....6....5....2....2....6....4....2....1....4....1....2....1
..7....6....5....7....6....6....4....7....4....7....2....7....3....7....3....2
..6....6....4....8....6....8....8....4....6....6....8....7....3....4....7....6
..4....6....5....4....9....7....8....8....4....5....9....9....6....4....6....7
.10....8....9....6....5....6....8....6...10....7....8....5....9....8....7....7
		

Formula

Empirical: a(n) = 6*a(n-1) -4*a(n-4) -22*a(n-5) -130*a(n-6) +7*a(n-8) +50*a(n-9) +66*a(n-10) +a(n-12) -6*a(n-13)

A250359 Number of length n arrays x(i), i=1..n with x(i) in i..i+6 and no value appearing more than 3 times.

Original entry on oeis.org

7, 49, 343, 2397, 16700, 115963, 803382, 5565230, 38548644, 266998350, 1849229664, 12807494729, 88702171850, 614332682800, 4254735401463, 29467361754942, 204084413284570, 1413443236278923, 9789192962198232, 67797768520165387
Offset: 1

Views

Author

R. H. Hardin, Nov 19 2014

Keywords

Comments

Column 6 of A250361

Examples

			Some solutions for n=6
..1....3....5....1....1....1....1....0....4....1....2....4....5....3....2....2
..1....4....2....2....6....7....3....6....7....7....1....6....6....6....5....1
..7....8....7....7....4....3....2....6....3....4....8....8....8....7....7....5
..4....3....4....7....3....5....6....8....8....4....4....7....6....3....4....7
..7....7....7....6....9....7....7....5...10....4....4....4....7....9....5...10
..7....9....5....6....6....8....6....7....8....6....7....5....9....6....7....8
		

Formula

Empirical: a(n) = 7*a(n-1) -8*a(n-4) -40*a(n-5) -265*a(n-6) -1800*a(n-7) +38*a(n-8) +336*a(n-9) +1937*a(n-10) +3833*a(n-11) +6318*a(n-12) +303*a(n-13) -1245*a(n-14) -3056*a(n-15) -1258*a(n-16) +725*a(n-17) +1024*a(n-18) +343*a(n-19) +34*a(n-20) -137*a(n-21) -77*a(n-22) +47*a(n-24) +14*a(n-25)

A250360 Number of length n arrays x(i), i=1..n with x(i) in i..i+7 and no value appearing more than 3 times.

Original entry on oeis.org

8, 64, 512, 4091, 32608, 259106, 2052904, 16234706, 128373416, 1015004124, 8024737888, 63441430784, 501536079048, 3964832287906, 31343315384096, 247778886499164, 1958768810680376, 15484663643904612, 122410935014171288
Offset: 1

Views

Author

R. H. Hardin, Nov 19 2014

Keywords

Comments

Column 7 of A250361

Examples

			Some solutions for n=5
..7....4....3....7....1....7....4....4....3....7....4....5....6....7....1....0
..7....1....8....5....6....3....2....1....2....1....8....3....5....5....2....5
..6....7....9....3....7....3....3....4....6....4....7....3....7....6....6....8
..5...10....7...10...10....4....6....7....6....6....6....5....9....8....3....5
.11....8....8....4....7....6....7....9....6....8....4...11...11...11....5...10
		

Formula

Empirical: a(n) = 8*a(n-1) -16*a(n-4) -64*a(n-5) -488*a(n-6) -3752*a(n-7) -29038*a(n-8) +1592*a(n-9) +11770*a(n-10) +66616*a(n-11) +151100*a(n-12) +472248*a(n-13) +953904*a(n-14) +183480*a(n-15) -568091*a(n-16) -1229632*a(n-17) -708460*a(n-18) -48256*a(n-19) +682669*a(n-20) -62120*a(n-21) +527060*a(n-22) +1075872*a(n-23) +1391771*a(n-24) +726760*a(n-25) +633398*a(n-26) +879696*a(n-27) +723511*a(n-28) -757912*a(n-29) -103140*a(n-30) +79256*a(n-31) +602486*a(n-32) -304224*a(n-33) -111134*a(n-34) -350584*a(n-35) +418679*a(n-36) -76624*a(n-37) +104514*a(n-38) -256568*a(n-39) +138277*a(n-40) -37600*a(n-41) +136030*a(n-42) -105232*a(n-43) +18365*a(n-44) -15688*a(n-45) +34876*a(n-46) -16992*a(n-47) -905*a(n-48) -4336*a(n-49) -24*a(n-50) -1968*a(n-52) -192*a(n-53) +12*a(n-56)

A250362 Number of length 4 arrays x(i), i=1..4 with x(i) in i..i+n and no value appearing more than 3 times.

Original entry on oeis.org

16, 81, 255, 623, 1293, 2397, 4091, 6555, 9993, 14633, 20727, 28551, 38405, 50613, 65523, 83507, 104961, 130305, 159983, 194463, 234237, 279821, 331755, 390603, 456953, 531417, 614631, 707255, 809973, 923493, 1048547, 1185891, 1336305
Offset: 1

Views

Author

R. H. Hardin, Nov 19 2014

Keywords

Examples

			Some solutions for n=6:
..1....2....1....3....1....5....3....5....0....0....5....0....5....3....2....4
..2....3....5....7....4....6....4....3....3....2....6....5....4....4....4....6
..8....4....2....5....2....8....7....2....6....5....4....7....6....7....3....2
..3....6....6....9....9....6....7....4....8....7....5....6....7....9....4....9
		

Crossrefs

Row 4 of A250361.

Formula

Empirical: a(n) = n^4 + 4*n^3 + 6*n^2 + 3*n + 3 for n>1.
Conjectures from Colin Barker, Nov 13 2018: (Start)
G.f.: x*(16 + x + 10*x^2 - 2*x^3 - 2*x^4 + x^5) / (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>6.
(End)

A250363 Number of length 5 arrays x(i), i=1..5 with x(i) in i..i+n and no value appearing more than 3 times.

Original entry on oeis.org

32, 243, 1016, 3094, 7712, 16700, 32608, 58826, 99704, 160672, 248360, 370718, 537136, 758564, 1047632, 1418770, 1888328, 2474696, 3198424, 4082342, 5151680, 6434188, 7960256, 9763034, 11878552, 14345840, 17207048, 20507566, 24296144
Offset: 1

Views

Author

R. H. Hardin, Nov 19 2014

Keywords

Examples

			Some solutions for n=6:
..1....2....1....2....5....3....5....4....4....3....3....6....2....2....1....3
..3....2....7....4....6....5....5....3....1....1....5....2....7....5....1....7
..6....2....6....5....8....2....4....3....5....7....6....5....8....6....3....4
..4....3....4....8....8....5....6....9....7....4....6....8....4....5....9....9
..4....7....9....4...10...10...10....9....4...10....4...10....9....4...10...10
		

Crossrefs

Row 5 of A250361.

Formula

Empirical: a(n) = n^5 + 5*n^4 + 10*n^3 + 5*n^2 + 17*n + 2 for n>2.
Conjectures from Colin Barker, Nov 13 2018: (Start)
G.f.: x*(32 + 51*x + 38*x^2 + 3*x^3 + 8*x^4 - 29*x^5 + 22*x^6 - 5*x^7) / (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>8.
(End)

A250364 Number of length 6 arrays x(i), i=1..6 with x(i) in i..i+n and no value appearing more than 3 times.

Original entry on oeis.org

64, 729, 4048, 15365, 45866, 115963, 259106, 526505, 992530, 1760831, 2971178, 4807021, 7503770, 11357795, 16736146, 24086993, 33950786, 46972135, 63912410, 85663061, 113259658, 147896651, 190942850, 243957625, 308707826, 387185423
Offset: 1

Views

Author

R. H. Hardin, Nov 19 2014

Keywords

Examples

			Some solutions for n=6:
..2....1....5....4....5....4....1....0....0....1....5....4....5....5....0....4
..2....6....4....7....2....6....4....1....1....5....5....4....1....3....4....4
..3....8....6....7....2....7....6....3....7....4....8....8....6....2....7....7
..8....7....4....5....7....7....8....5....5....4....8....8....8....9....9....7
..8....7....4....5....4....7....4....9....8....8....4....9....6....8....4....8
..7...11....7...10....7....8....8....6....5....6...10....7....9....6....7....8
		

Crossrefs

Row 6 of A250361.

Formula

Empirical: a(n) = n^6 + 6*n^5 + 15*n^4 + 5*n^3 + 57*n^2 + 13*n + 1 for n>3.
Conjectures from Colin Barker, Nov 13 2018: (Start)
G.f.: x*(64 + 281*x + 289*x^2 + 98*x^3 + 44*x^4 + 57*x^5 - 405*x^6 + 482*x^7 - 232*x^8 + 42*x^9) / (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>10.
(End)

A250365 Number of length 7 arrays x(i), i=1..7 with x(i) in i..i+n and no value appearing more than 3 times.

Original entry on oeis.org

128, 2187, 16128, 76300, 272760, 803382, 2052904, 4698744, 9854280, 19251970, 35471832, 62220324, 104664664, 169827630, 267047880, 408510832, 609855144, 890859834, 1276217080, 1796395740, 2488600632, 3397832614, 4578054504
Offset: 1

Views

Author

R. H. Hardin, Nov 19 2014

Keywords

Comments

Row 7 of A250361

Examples

			Some solutions for n=4
..4....3....2....2....1....2....1....0....2....3....3....1....0....1....4....4
..4....5....4....2....5....2....1....2....5....1....2....2....5....2....4....5
..3....3....6....4....6....2....2....5....4....2....2....6....6....3....4....4
..5....7....6....5....3....4....7....3....6....6....6....6....7....6....3....7
..4....8....4....5....5....8....7....5....4....8....7....8....4....8....5....6
..6....7....5....7....5....6....9....8....9....8....9....7....5....9....9....5
..6....7....7....7....7....9....9....8....8...10....6...10...10....7....8....8
		

Formula

Empirical: a(n) = n^7 + 7*n^6 + 21*n^5 + 147*n^3 + 49*n^2 + 7*n for n>4
Showing 1-8 of 8 results.