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 12 results. Next

A219680 Number of n X 2 arrays of the minimum value of corresponding elements and their horizontal, vertical or antidiagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..2 n X 2 array.

Original entry on oeis.org

3, 4, 9, 19, 35, 60, 98, 154, 234, 345, 495, 693, 949, 1274, 1680, 2180, 2788, 3519, 4389, 5415, 6615, 8008, 9614, 11454, 13550, 15925, 18603, 21609, 24969, 28710, 32860, 37448, 42504, 48059, 54145, 60795, 68043, 75924, 84474, 93730, 103730, 114513
Offset: 1

Views

Author

R. H. Hardin, Nov 25 2012

Keywords

Comments

Column 2 of A219686.

Examples

			All solutions for n=3:
..1..1....1..1....0..0....0..0....1..0....1..1....2..2....0..0....0..0
..1..1....1..0....0..0....0..0....0..0....1..1....2..2....0..0....0..0
..2..2....0..0....1..1....1..2....0..0....1..1....2..2....2..2....0..0
		

Crossrefs

Cf. A219686.

Formula

Empirical: a(n) = (1/24)*n^4 - (1/4)*n^3 + (47/24)*n^2 - (7/4)*n for n>2.
Conjectures from Colin Barker, Jul 26 2018: (Start)
G.f.: x*(3 - 11*x + 19*x^2 - 16*x^3 + 5*x^4 + 2*x^5 - x^6) / (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>7.
(End)

A219681 Number of nX3 arrays of the minimum value of corresponding elements and their horizontal, vertical or antidiagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..2 nX3 array.

Original entry on oeis.org

6, 8, 31, 99, 269, 655, 1506, 3356, 7278, 15335, 31362, 62286, 120292, 226281, 415250, 744464, 1305597, 2242405, 3775972, 6240154, 10130551, 16171179, 25404010, 39307716, 59953312, 90205963, 133984022, 196588422, 285117878, 408987989
Offset: 1

Views

Author

R. H. Hardin Nov 25 2012

Keywords

Comments

Column 3 of A219686

Examples

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

Formula

Empirical: a(n) = (1/39916800)*n^11 - (1/3628800)*n^10 + (1/362880)*n^9 + (5/24192)*n^8 - (5639/1209600)*n^7 + (11267/172800)*n^6 - (26249/90720)*n^5 - (45251/36288)*n^4 + (5226461/226800)*n^3 - (303403/3150)*n^2 + (229729/1386)*n - 88 for n>4

A219682 Number of n X 4 arrays of the minimum value of corresponding elements and their horizontal, vertical or antidiagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..2 n X 4 array.

Original entry on oeis.org

10, 14, 87, 427, 1688, 5726, 18486, 59458, 189516, 589078, 1771979, 5155016, 14529474, 39751677, 105748979, 273953703, 692141498, 1707798168, 4120669743, 9734318169, 22538154434, 51195509983, 114191870360, 250314850722
Offset: 1

Views

Author

R. H. Hardin, Nov 25 2012

Keywords

Comments

Column 4 of A219686.

Examples

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

Crossrefs

Cf. A219686.

Formula

Empirical: a(n) = (1/8841761993739701954543616000000)*n^29 - (1/50814724101952310083584000000)*n^28 + (1/580739704022312115240960000)*n^27 - (1/53772194816880751411200000)*n^26 - (67/6768528018908066611200000)*n^25 + (4643/4136322678221596262400000)*n^24 - (1309733/24054307267196359802880000)*n^23 + (776987/2265985467199657082880000)*n^22 + (410911/2972563908172185600000)*n^21 - (490056821/49047304484841062400000)*n^20 + (16372002799/49801878399992463360000)*n^19 - (968981309/631017952436551680000)*n^18 - (17406895711696783/46512333274098224332800000)*n^17 + (8682271622870311/456003267393119846400000)*n^16 - (1074465658101893/2368848142301921280000)*n^15 + (12853594615136699/4342888260886855680000)*n^14 + (3714463850051933851/21296855894733619200000)*n^13 - (16329337796841689161/2366317321637068800000)*n^12 + (563272404080038801903/4456702186362961920000)*n^11 - (41790908888053128958991/38624752281812336640000)*n^10 - (2068970873910075110920537/379350245624942592000000)*n^9 + (12606404340006385030084357/42150027291660288000000)*n^8 - (2180783444974657064143769/497154168055480320000)*n^7 + (96109697881649790417637807/2692918410300518400000)*n^6 - (136580940782604083515955587/928240815671769600000)*n^5 - (1259605322569179919156739/12605739472085760000)*n^4 + (11723883931469901490135337/2431106898187968000)*n^3 - (25408893790340784114283/964724959598400)*n^2 + (5037095951528247967/77636318760)*n - 61265531 for n>13.

A219683 Number of nX5 arrays of the minimum value of corresponding elements and their horizontal, vertical or antidiagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..2 nX5 array.

Original entry on oeis.org

15, 22, 208, 1531, 8964, 44816, 220182, 1116208, 5697556, 28354294, 135630422, 623221049, 2761665622, 11842133497, 49237357701, 198775751684, 780253085746, 2982381614057, 11117260746432, 40470971856226, 144060818799022
Offset: 1

Views

Author

R. H. Hardin Nov 25 2012

Keywords

Comments

Column 5 of A219686

Examples

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

A219684 Number of nX6 arrays of the minimum value of corresponding elements and their horizontal, vertical or antidiagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..2 nX6 array.

Original entry on oeis.org

21, 32, 452, 5031, 44736, 344926, 2706117, 22404783, 187497531, 1518906665, 11728070120, 86620862097, 616844079105, 4256996307319, 28523072830335, 185674613829792, 1175484129892778, 7248518396992789, 43607030016608124
Offset: 1

Views

Author

R. H. Hardin Nov 25 2012

Keywords

Comments

Column 6 of A219686

Examples

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

A219687 Number of 3 X n arrays of the minimum value of corresponding elements and their horizontal, vertical or antidiagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..2 3 X n array.

Original entry on oeis.org

6, 9, 31, 87, 208, 452, 922, 1799, 3394, 6234, 11196, 19713, 34085, 57937, 96878, 159429, 258304, 412146, 647840, 1003547, 1532627, 2308645, 3431682, 5036203, 7300766, 10459890, 14818436, 20768893, 28812001, 39581185, 53871318, 72672377
Offset: 1

Views

Author

R. H. Hardin, Nov 25 2012

Keywords

Comments

Row 3 of A219686.

Examples

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

Crossrefs

Cf. A219686.

Formula

Empirical: a(n) = (1/181440)*n^9 - (1/4032)*n^8 + (31/4320)*n^7 - (37/288)*n^6 + (14137/8640)*n^5 - (7859/576)*n^4 + (3420947/45360)*n^3 - (240133/1008)*n^2 + (63709/180)*n - 79 for n>6.
Conjectures from Colin Barker, Jul 26 2018: (Start)
G.f.: x*(6 - 51*x + 211*x^2 - 538*x^3 + 913*x^4 - 1055*x^5 + 824*x^6 - 413*x^7 + 110*x^8 + 8*x^9 - 27*x^10 + 23*x^11 - 12*x^12 + x^13 + 3*x^14 - x^15) / (1 - x)^10.
a(n) = 10*a(n-1) - 45*a(n-2) + 120*a(n-3) - 210*a(n-4) + 252*a(n-5) - 210*a(n-6) + 120*a(n-7) - 45*a(n-8) + 10*a(n-9) - a(n-10) for n>15.
(End)

A219688 Number of 4Xn arrays of the minimum value of corresponding elements and their horizontal, vertical or antidiagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..2 4Xn array.

Original entry on oeis.org

10, 19, 99, 427, 1531, 5031, 15763, 47784, 140586, 401745, 1116450, 3022129, 7979699, 20573716, 51835099, 127704345, 307858090, 726741861, 1681297548, 3815152314, 8498764539, 18601381870, 40034714647, 84794977698, 176874740063
Offset: 1

Views

Author

R. H. Hardin Nov 25 2012

Keywords

Comments

Row 4 of A219686

Examples

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

Formula

Empirical: a(n) = (1/71811157608013824000000)*n^25 - (101/17234677825923317760000)*n^24 + (5449/4308669456480829440000)*n^23 - (68021/374666909259202560000)*n^22 + (9824237/510909421717094400000)*n^21 - (21583/13610640605184000)*n^20 + (5371647499/51090942171709440000)*n^19 - (394323599/68948639907840000)*n^18 + (45438295453/175751435059200000)*n^17 - (16515462281/1687213776568320)*n^16 + (542084002355513/1739939207086080000)*n^15 - (28192245777209/3381806039040000)*n^14 + (3250324207416831463/17399392070860800000)*n^13 - (1612171294329183241/463983788556288000)*n^12 + (2781152508058068181/52725430517760000)*n^11 - (757894220102779469/1198305239040000)*n^10 + (37334585059613913334793/6722492391014400000)*n^9 - (107120698751683891/3939922280448)*n^8 - (79214526965365782185939/798295971432960000)*n^7 + (49706772664271871813409/13646084981760000)*n^6 - (2005940155459581015843920483/48784753809792000000)*n^5 + (15777623834516738464154783/54205282010880000)*n^4 - (17331604984082844755616061/12467214862502400)*n^3 + (215362834119633956818141/49473074851200)*n^2 - (4207251609878775049/524924400)*n + 6438609162 for n>14

A219689 Number of 5Xn arrays of the minimum value of corresponding elements and their horizontal, vertical or antidiagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..2 5Xn array.

Original entry on oeis.org

15, 35, 269, 1688, 8964, 44736, 219216, 1062133, 5046678, 23361295, 105246826, 462379361, 1984693730, 8329188237, 34174571720, 137072090506, 537533392034, 2061741321158, 7738348853856, 28437341923159, 102381325106959
Offset: 1

Views

Author

R. H. Hardin Nov 25 2012

Keywords

Comments

Row 5 of A219686

Examples

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

A219690 Number of 6Xn arrays of the minimum value of corresponding elements and their horizontal, vertical or antidiagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..2 6Xn array.

Original entry on oeis.org

21, 60, 655, 5726, 44816, 344926, 2709320, 21474269, 167685059, 1273322836, 9386203438, 67340577300, 471427290355, 3224592437317, 21562151377146, 141010883018273, 902366368908706, 5653483899077449, 34695071833947322
Offset: 1

Views

Author

R. H. Hardin Nov 25 2012

Keywords

Comments

Row 6 of A219686

Examples

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

A219679 Number of n X n arrays of the minimum value of corresponding elements and their horizontal, vertical or antidiagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..2 n X n array.

Original entry on oeis.org

3, 4, 31, 427, 8964, 344926, 35011623, 10451333258
Offset: 1

Views

Author

R. H. Hardin Nov 25 2012

Keywords

Comments

Diagonal of A219686

Examples

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