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 11 results. Next

A220616 Number of ways to reciprocally link elements of an n X 3 array either to themselves or to exactly one horizontal, diagonal and antidiagonal neighbor.

Original entry on oeis.org

3, 21, 125, 765, 4657, 28373, 172833, 1052829, 6413369, 39067429, 237981569, 1449678893, 8830805161, 53793374581, 327685538769, 1996115937021, 12159458878905, 74070066514885, 451202212873441, 2748525099013581
Offset: 1

Views

Author

R. H. Hardin, Dec 17 2012

Keywords

Comments

Column 3 of A220621.

Examples

			Some solutions for n=3 0=self 1=nw 3=ne 4=w 6=e 7=sw 9=se (reciprocal directions total 10):
..0..6..4....0..7..0....0..7..0....0..0..0....6..4..0....0..6..4....0..9..7
..0..6..4....3..6..4....3..7..7....0..9..7....0..7..0....6..4..0....0..3..1
..0..0..0....0..6..4....3..3..0....0..3..1....3..0..0....6..4..0....6..4..0
		

Crossrefs

Cf. A220621.

Formula

Empirical: a(n) = 7*a(n-1) - 4*a(n-2) - 10*a(n-3) + 4*a(n-4).
Empirical g.f.: x*(1 + 2*x)*(3 - 6*x + 2*x^2) / (1 - 7*x + 4*x^2 + 10*x^3 - 4*x^4). - Colin Barker, Aug 01 2018

A220617 Number of ways to reciprocally link elements of an nX4 array either to themselves or to exactly one horizontal, diagonal and antidiagonal neighbor.

Original entry on oeis.org

5, 87, 1189, 17084, 243119, 3466455, 49406943, 704243629, 10038098456, 143080761421, 2039439299333, 29069688249415, 414352491974681, 5906082889319188, 84183915242486395, 1199937711608731991
Offset: 1

Views

Author

R. H. Hardin Dec 17 2012

Keywords

Comments

Column 4 of A220621

Examples

			Some solutions for n=3 0=self 1=nw 3=ne 4=w 6=e 7=sw 9=se (reciprocal directions total 10)
..0..9..6..4....0..0..6..4....0..6..4..0....9..7..0..0....9..7..0..0
..0..7..1..0....0..0..0..0....0..0..0..7....3..1..6..4....3..1..6..4
..3..0..0..0....0..0..6..4....0..0..3..0....0..0..0..0....0..6..4..0
		

Formula

Empirical: a(n) = 16*a(n-1) -18*a(n-2) -114*a(n-3) +230*a(n-4) -66*a(n-5) -78*a(n-6) +48*a(n-7) -4*a(n-8) -4*a(n-9) +a(n-10)

A220618 Number of ways to reciprocally link elements of an nX5 array either to themselves or to exactly one horizontal, diagonal and antidiagonal neighbor.

Original entry on oeis.org

8, 317, 9176, 282777, 8608738, 262680517, 8011414792, 244357686173, 7453056468816, 227323314349577, 6933510501158596, 211476640729594693, 6450176661330373022, 196734631145079828705, 6000535646826871036976
Offset: 1

Views

Author

R. H. Hardin Dec 17 2012

Keywords

Comments

Column 5 of A220621

Examples

			Some solutions for n=3 0=self 1=nw 3=ne 4=w 6=e 7=sw 9=se (reciprocal directions total 10)
..0..0..9..9..0....0..0..0..6..4....6..4..7..0..0....0..0..6..4..0
..0..7..0..1..1....0..6..4..9..0....9..3..0..9..0....9..6..4..6..4
..3..0..6..4..0....0..0..0..0..1....0..1..0..0..1....0..1..0..0..0
		

Formula

Empirical: a(n) = 38*a(n-1) -189*a(n-2) -1434*a(n-3) +6910*a(n-4) -3882*a(n-5) -9380*a(n-6) +9742*a(n-7) -477*a(n-8) -1476*a(n-9) +125*a(n-10)

A220619 Number of ways to reciprocally link elements of an nX6 array either to themselves or to exactly one horizontal, diagonal and antidiagonal neighbor.

Original entry on oeis.org

13, 1215, 76955, 5280827, 356768525, 24177895648, 1637496710797, 110916199227139, 7512747980759983, 508867505795261823, 34467532553765146717, 2334617570886588879553, 158132555108084876751600
Offset: 1

Views

Author

R. H. Hardin Dec 17 2012

Keywords

Comments

Column 6 of A220621

Examples

			Some solutions for n=3 0=self 1=nw 3=ne 4=w 6=e 7=sw 9=se (reciprocal directions total 10)
..6..4..0..6..4..0....0..7..9..7..0..0....9..9..9..0..6..4....6..4..9..0..9..0
..0..9..7..9..9..0....3..7..3..1..6..4....0..1..1..1..7..0....9..9..0..1..7..1
..0..3..1..0..1..1....3..0..0..6..4..0....0..6..4..3..6..4....0..1..1..3..0..0
		

Formula

Empirical: a(n) = 75*a(n-1) -234*a(n-2) -18880*a(n-3) +81906*a(n-4) +899610*a(n-5) -3495200*a(n-6) -14871391*a(n-7) +57262153*a(n-8) +94978240*a(n-9) -425367914*a(n-10) -207014564*a(n-11) +1449829450*a(n-12) +111910344*a(n-13) -2364082704*a(n-14) -29030256*a(n-15) +1700883948*a(n-16) +349734858*a(n-17) -215936884*a(n-18) -545425394*a(n-19) -380424104*a(n-20) +341201464*a(n-21) +219237544*a(n-22) -120388312*a(n-23) -52194454*a(n-24) +28101292*a(n-25) +7351846*a(n-26) -4063344*a(n-27) -843527*a(n-28) +300917*a(n-29) +79254*a(n-30) -10858*a(n-31) -4326*a(n-32) +168*a(n-33) +112*a(n-34) -a(n-35) -a(n-36)

A220620 Number of ways to reciprocally link elements of an nX7 array either to themselves or to exactly one horizontal, diagonal and antidiagonal neighbor.

Original entry on oeis.org

21, 4565, 624227, 93905509, 13864972277, 2054706174413, 304265433695569, 45062687311719797, 6673721691080067317, 988374130647554935157, 146377412047334158410357, 21678380394232186381827093
Offset: 1

Views

Author

R. H. Hardin Dec 17 2012

Keywords

Comments

Column 7 of A220621

Examples

			Some solutions for n=3 0=self 1=nw 3=ne 4=w 6=e 7=sw 9=se (reciprocal directions total 10)
..0..7..9..0..0..0..7....0..7..6..4..6..4..0....0..7..0..0..0..9..0
..3..0..7..1..7..3..0....3..0..0..0..0..6..4....3..0..9..9..6..4..1
..0..3..0..3..6..4..0....6..4..0..0..0..0..0....0..6..4..1..1..0..0
		

Formula

Empirical: a(n) = 201*a(n-1) -6982*a(n-2) -189430*a(n-3) +9590330*a(n-4) -17036302*a(n-5) -2815039392*a(n-6) +24279361760*a(n-7) +198170224768*a(n-8) -2875481635520*a(n-9) -383756692624*a(n-10) +115334410373680*a(n-11) -283314863036560*a(n-12) -1777891655816032*a(n-13) +7541953262286912*a(n-14) +7231319523252480*a(n-15) -67620253084304384*a(n-16) +32587945923607040*a(n-17) +252473367356505600*a(n-18) -301020866429181440*a(n-19) -378989877588835840*a(n-20) +740276347708960768*a(n-21) +102424394439131136*a(n-22) -719256751312953344*a(n-23) +211285473650806784*a(n-24) +277487256139481088*a(n-25) -178573089681702912*a(n-26) -26529867221958656*a(n-27) +59859716422762496*a(n-28) -8012264149876736*a(n-29) -11308640300433408*a(n-30) +1932970382327808*a(n-31) +1107369538879488*a(n-32) -185816928223232*a(n-33) -37457215094784*a(n-34) -13028783292416*a(n-35) +6240587481088*a(n-36) -274877906944*a(n-37)

A220622 Number of ways to reciprocally link elements of an 3 X n array either to themselves or to exactly one horizontal, diagonal and antidiagonal neighbor.

Original entry on oeis.org

1, 22, 125, 1189, 9176, 76955, 624227, 5131406, 41957895, 343809419, 2814822600, 23053276257, 188779537161, 1545969533334, 12660108907789, 103675885828389, 849017313171328, 6952739324271787, 56937068599653211, 466266655043137726
Offset: 1

Views

Author

R. H. Hardin, Dec 17 2012

Keywords

Comments

Row 3 of A220621.

Examples

			Some solutions for n=3 0=self 1=nw 3=ne 4=w 6=e 7=sw 9=se (reciprocal directions total 10):
..6..4..0....0..6..4....0..7..0....0..0..0....6..4..0....0..7..0....0..7..0
..0..0..0....0..6..4....3..6..4....0..0..0....9..9..0....3..6..4....3..0..7
..0..0..0....6..4..0....0..6..4....0..6..4....0..1..1....0..0..0....0..3..0
		

Crossrefs

Cf. A220621.

Formula

Empirical: a(n) = 6*a(n-1) + 22*a(n-2) - 32*a(n-3) - 12*a(n-4) + 8*a(n-5) - 3*a(n-6).
Empirical g.f.: x*(1 + 16*x - 29*x^2 - 13*x^3 + 8*x^4 - 3*x^5) / (1 - 6*x - 22*x^2 + 32*x^3 + 12*x^4 - 8*x^5 + 3*x^6). - Colin Barker, Aug 01 2018

A220623 Number of ways to reciprocally link elements of an 4Xn array either to themselves or to exactly one horizontal, diagonal and antidiagonal neighbor.

Original entry on oeis.org

1, 71, 765, 17084, 282777, 5280827, 93905509, 1703300073, 30648000256, 553256525421, 9974206108397, 179912817659011, 3244530759637569, 58516690759430228, 1055339507419304093, 19033159346284815815
Offset: 1

Views

Author

R. H. Hardin Dec 17 2012

Keywords

Comments

Row 4 of A220621

Examples

			Some solutions for n=3 0=self 1=nw 3=ne 4=w 6=e 7=sw 9=se (reciprocal directions total 10)
..0..6..4....6..4..0....6..4..0....0..6..4....0..7..0....0..0..7....9..9..0
..0..6..4....6..4..0....0..9..0....0..9..0....3..9..0....0..3..0....0..1..1
..0..7..7....0..0..0....9..0..1....0..0..1....0..0..1....9..7..0....6..4..0
..3..3..0....0..6..4....0..1..0....0..0..0....6..4..0....3..1..0....6..4..0
		

Formula

Empirical: a(n) = 14*a(n-1) +98*a(n-2) -452*a(n-3) -102*a(n-4) +876*a(n-5) -144*a(n-6) -268*a(n-7) +22*a(n-8) -8*a(n-9) +15*a(n-10)

A220624 Number of ways to reciprocally link elements of an 5Xn array either to themselves or to exactly one horizontal, diagonal and antidiagonal neighbor.

Original entry on oeis.org

1, 228, 4657, 243119, 8608738, 356768525, 13864972277, 553125347136, 21831846871613, 865461975018339, 34247958158855874, 1356237159188241529, 53691862459540232153, 2125854494007156918632, 84166119627538600335289
Offset: 1

Views

Author

R. H. Hardin Dec 17 2012

Keywords

Comments

Row 5 of A220621

Examples

			Some solutions for n=3 0=self 1=nw 3=ne 4=w 6=e 7=sw 9=se (reciprocal directions total 10)
..9..0..0....0..7..0....6..4..0....0..7..0....0..6..4....0..0..7....0..6..4
..0..1..0....3..7..0....0..0..0....3..7..0....0..9..0....0..3..0....0..7..0
..6..4..7....3..6..4....0..6..4....3..6..4....0..0..1....0..9..0....3..7..0
..9..3..0....0..7..7....0..6..4....6..4..0....6..4..0....6..4..1....3..0..0
..0..1..0....3..3..0....0..6..4....6..4..0....0..0..0....0..6..4....6..4..0
		

Formula

Empirical: a(n) = 29*a(n-1) +557*a(n-2) -4948*a(n-3) -24662*a(n-4) +187560*a(n-5) +182180*a(n-6) -1893504*a(n-7) -127344*a(n-8) +6325072*a(n-9) +132352*a(n-10) -7384448*a(n-11) -1323456*a(n-12) +2439808*a(n-13) +987648*a(n-14) -7168*a(n-15) -69632*a(n-16) +32768*a(n-17)

A220625 Number of ways to reciprocally link elements of an 6Xn array either to themselves or to exactly one horizontal, diagonal and antidiagonal neighbor.

Original entry on oeis.org

1, 733, 28373, 3466455, 262680517, 24177895648, 2054706174413, 180411767818111, 15630369162961753, 1361611598697855401, 118348460320274885509, 10296062072472866977053, 895398179175506044479552
Offset: 1

Views

Author

R. H. Hardin Dec 17 2012

Keywords

Comments

Row 6 of A220621

Examples

			Some solutions for n=3 0=self 1=nw 3=ne 4=w 6=e 7=sw 9=se (reciprocal directions total 10)
..0..6..4....6..4..0....0..6..4....0..0..0....0..9..0....0..0..0....9..6..4
..0..0..0....6..4..0....9..9..0....0..9..0....9..7..1....0..0..0....0..1..7
..0..7..0....0..0..0....0..1..1....0..7..1....3..1..7....6..4..0....0..3..0
..3..7..0....9..7..0....6..4..7....3..0..0....0..3..0....6..4..7....0..6..4
..3..0..0....3..1..0....0..3..0....9..7..0....0..7..0....0..3..0....0..6..4
..6..4..0....0..6..4....0..6..4....3..1..0....3..0..0....0..0..0....0..6..4
		

Formula

Empirical: a(n) = 63*a(n-1) +2862*a(n-2) -60440*a(n-3) -824202*a(n-4) +18146150*a(n-5) -20045386*a(n-6) -921241585*a(n-7) +3855313257*a(n-8) +9737277088*a(n-9) -97429928112*a(n-10) +108733427540*a(n-11) +757492139660*a(n-12) -1932297359512*a(n-13) -1293178837092*a(n-14) +7244830922052*a(n-15) -3341781023928*a(n-16) -7386155450412*a(n-17) +15850519492508*a(n-18) -14572332601872*a(n-19) -15900073555920*a(n-20) +32949026690632*a(n-21) -1615780730832*a(n-22) -14531450950368*a(n-23) +3100647563872*a(n-24) +425129425324*a(n-25) -23935477836*a(n-26) +300359574120*a(n-27) +63008127325*a(n-28) +37808128429*a(n-29) -35095894230*a(n-30) -6841941084*a(n-31) -750501810*a(n-32) +796187034*a(n-33) -8202438*a(n-34) -1789695*a(n-35) -552825*a(n-36)

A220626 Number of ways to reciprocally link elements of an 7Xn array either to themselves or to exactly one horizontal, diagonal and antidiagonal neighbor.

Original entry on oeis.org

1, 2356, 172833, 49406943, 8011414792, 1637496710797, 304265433695569, 58792186589810692, 11178980566694533181, 2139705888320467053783, 408438850253554118760672, 78052060676212571885932839
Offset: 1

Views

Author

R. H. Hardin Dec 17 2012

Keywords

Comments

Row 7 of A220621

Examples

			Some solutions for n=3 0=self 1=nw 3=ne 4=w 6=e 7=sw 9=se (reciprocal directions total 10)
..0..7..0....0..9..0....0..7..0....0..7..0....0..0..0....0..6..4....0..6..4
..3..9..0....0..7..1....3..7..0....3..7..0....0..7..0....6..4..0....6..4..0
..0..9..1....3..0..0....3..6..4....3..7..0....3..7..0....9..7..0....0..7..0
..0..7..1....0..6..4....0..9..0....3..7..0....3..6..4....3..1..0....3..0..0
..3..7..7....0..7..0....6..4..1....3..0..7....6..4..0....0..6..4....0..6..4
..3..3..0....3..9..0....0..7..0....0..3..0....0..7..7....0..9..0....0..9..7
..6..4..0....6..4..1....3..0..0....0..0..0....3..3..0....0..0..1....0..3..1
		

Formula

Empirical: a(n) = 138*a(n-1) +14704*a(n-2) -766832*a(n-3) -28294686*a(n-4) +1524422160*a(n-5) +1505265612*a(n-6) -657053175478*a(n-7) +2442897908716*a(n-8) +121219040652652*a(n-9) -477157654573460*a(n-10) -11078652756436422*a(n-11) +25390010604819866*a(n-12) +462672915130668714*a(n-13) +539039443446704064*a(n-14) -2300750637803847292*a(n-15) -106740256054565434670*a(n-16) -525485832852749557732*a(n-17) +4696460371559704057208*a(n-18) +20625415710589823362046*a(n-19) -106635774503822778533068*a(n-20) -359528017386314652554916*a(n-21) +1434757125253268865522192*a(n-22) +3342419613209446332183086*a(n-23) -12412241250913071404180671*a(n-24) -16009499469215852930982996*a(n-25) +76301561379273628920121480*a(n-26) +16714074472917107500322288*a(n-27) -350287053489912157977657276*a(n-28) +246449516277847669520873504*a(n-29) +1085617448661458748927032552*a(n-30) -1465223004596924237606500724*a(n-31) -1803274128034881610349327880*a(n-32) +3516508917367494771271844688*a(n-33) +684156230546695030907577128*a(n-34) -3371221939576667129347102948*a(n-35) +1774979612482525654248800356*a(n-36) -305960447612303854340530276*a(n-37) -1782960715267049838679389320*a(n-38) +2423880586788763938819482584*a(n-39) +346133788947372810781005124*a(n-40) -1729222868084540777448834968*a(n-41) +266878793131853890601352560*a(n-42) +960049718041715410291124004*a(n-43) -832232703419849484865464104*a(n-44) +183729276922163315799804240*a(n-45) +342523577682868354239921104*a(n-46) -399235979100028148521176332*a(n-47) +120009650652405707129304857*a(n-48) +46551250238969402512573930*a(n-49) -38145714869513667277222872*a(n-50) +7918437257271901469718272*a(n-51) -2635055091367948207000262*a(n-52) +3607443742375711101808688*a(n-53) -2000242792241551629394644*a(n-54) +21899529024947808110922*a(n-55) +356306994648073904663420*a(n-56) -93971649444626647347932*a(n-57) -1450295589197392760916*a(n-58) -1024247136206230000278*a(n-59) +1187176424264486875426*a(n-60) -134415977089345498662*a(n-61) +55717506862783032360*a(n-62) -21553683350249918364*a(n-63) +2674908537678317322*a(n-64) -173994425830551588*a(n-65) +60988142986744248*a(n-66) -8768894100846210*a(n-67) -458136027067500*a(n-68) +84709288120500*a(n-69) -1129653540000*a(n-70) +1588978518750*a(n-71) -165767765625*a(n-72)
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