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 10 results.

A269600 Number of length-n 0..n arrays with no repeated value differing from the previous repeated value by one or less.

Original entry on oeis.org

2, 9, 60, 572, 7030, 105892, 1886252, 38768412, 902743646, 23482784400, 674804472216, 21227322458468, 725465523386294, 26765145874993234, 1060182321437102136, 44874027105660248520, 2021234030434596074938
Offset: 1

Views

Author

R. H. Hardin, Mar 01 2016

Keywords

Comments

Diagonal of A269606.

Examples

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

Crossrefs

Cf. A269606.

A269601 Number of length-n 0..2 arrays with no repeated value differing from the previous repeated value by one or less.

Original entry on oeis.org

3, 9, 24, 62, 154, 376, 902, 2142, 5040, 11786, 27418, 63544, 146822, 338478, 778944, 1790282, 4110730, 9432424, 21633542, 49603134, 113717328, 260691722, 597649402, 1370287384, 3142264070, 7206988878, 16533117792, 37935980618, 87065571946
Offset: 1

Views

Author

R. H. Hardin, Mar 01 2016

Keywords

Examples

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

Crossrefs

Column 2 of A269606.

Formula

Empirical: a(n) = 5*a(n-1) - 5*a(n-2) - 8*a(n-3) + 12*a(n-4).
Empirical g.f.: x*(3 - 6*x - 6*x^2 + 11*x^3) / ((1 - 2*x)^2*(1 - x - 3*x^2)). - Colin Barker, Jan 24 2019

A269602 Number of length-n 0..4 arrays with no repeated value differing from the previous repeated value by one or less.

Original entry on oeis.org

5, 25, 120, 572, 2692, 12570, 58280, 268704, 1233046, 5636046, 25675580, 116635916, 528551090, 2390183046, 10789164304, 48625122028, 218845692934, 983773248134, 4417701453060, 19819733378212, 88847987191058, 398004177820814
Offset: 1

Views

Author

R. H. Hardin, Mar 01 2016

Keywords

Examples

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

Crossrefs

Column 4 of A269606.

Formula

Empirical: a(n) = 13*a(n-1) - 49*a(n-2) - 5*a(n-3) + 292*a(n-4) - 70*a(n-5) - 658*a(n-6) - 344*a(n-7).
Empirical g.f.: x*(5 - 40*x + 40*x^2 + 262*x^3 - 199*x^4 - 748*x^5 - 362*x^6) / ((1 - 4*x)*(1 - 9*x + 13*x^2 + 57*x^3 - 64*x^4 - 186*x^5 - 86*x^6)). - Colin Barker, Jan 24 2019

A269603 Number of length-n 0..5 arrays with no repeated value differing from the previous repeated value by one or less.

Original entry on oeis.org

6, 36, 210, 1220, 7030, 40288, 229754, 1304934, 7385898, 41679780, 234601902, 1317558578, 7385249086, 41325945826, 230904832646, 1288466651340, 7181415415962, 39985405920156, 222432351559566, 1236355637246456
Offset: 1

Views

Author

R. H. Hardin, Mar 01 2016

Keywords

Examples

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

Crossrefs

Column 5 of A269606.

Programs

  • Maple
    T:= Matrix(42,42):
    for x from 0 to 5 do
      for v from 0 to 6 do
        i:= 1 + x + 6*v;
        for y in {$0..5} minus {x} do
          T[i,1+y+6*v]:= 1;
        od:
        if abs(x-v) > 1 or v=6 then T[i,1+x+6*x]:= 1 fi
    od od:
    u:= Vector([0$36,1$6]): v:= Vector(42,1):
    Tv[1]:= v:
    for n from 2 to 50 do Tv[n]:= T . Tv[n-1] od:
    seq(u^%T . Tv[n], n=1..50); # Robert Israel, Jan 24 2019

Formula

Empirical: a(n) = 17*a(n-1) - 91*a(n-2) + 83*a(n-3) + 542*a(n-4) - 550*a(n-5) - 1651*a(n-6) - 745*a(n-7).
Empirical g.f.: 2*x*(3 - 33*x + 72*x^2 + 214*x^3 - 420*x^4 - 922*x^5 - 393*x^6) / ((1 - 5*x)*(1 - 12*x + 31*x^2 + 72*x^3 - 182*x^4 - 360*x^5 - 149*x^6)). - Colin Barker, Jan 24 2019
Empirical recursion verified - see link. - Robert Israel, Jan 24 2019

A269604 Number of length-n 0..6 arrays with no repeated value differing from the previous repeated value by one or less.

Original entry on oeis.org

7, 49, 336, 2298, 15630, 105892, 714874, 4811578, 32300252, 216337084, 1446056046, 9648789758, 64281141440, 427655897226, 2841661493142, 18861464959350, 125070420653458, 828618463551536, 5485481885293294, 36288577806336542
Offset: 1

Views

Author

R. H. Hardin, Mar 01 2016

Keywords

Examples

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

Crossrefs

Column 6 of A269606.

Programs

  • Maple
    with(LinearAlgebra):
    T:= Matrix(56,56):
    for x from 0 to 6 do
      for v from 0 to 7 do
        i:= 1 + x + 7*v;
        for y in {$0..6} minus {x} do
          T[i,1+y+7*v]:= 1;
        od:
        if abs(x-v) > 1 or v=7 then T[i,1+x+7*x]:= 1 fi
    od od:
    u:= Vector([0$49,1$7]): v:= Vector(56,1):
    Tv[1]:= v:
    for n from 2 to 50 do Tv[n]:= T . Tv[n-1] od:
    seq(u^%T . Tv[n], n=1..50); # Robert Israel, Jan 24 2019

Formula

Empirical: a(n) = 26*a(n-1) - 243*a(n-2) + 833*a(n-3) + 567*a(n-4) - 7567*a(n-5) - 1006*a(n-6) + 27361*a(n-7) + 31306*a(n-8) + 9984*a(n-9).
Empirical g.f.: x*(7 - 133*x + 763*x^2 - 362*x^3 - 7256*x^4 + 3224*x^5 + 32851*x^6 + 34133*x^7 + 10511*x^8) / ((1 - 6*x)*(1 - 20*x + 123*x^2 - 95*x^3 - 1137*x^4 + 745*x^5 + 5476*x^6 + 5495*x^7 + 1664*x^8)). - Colin Barker, Jan 24 2019
Empirical recursion verified: see link. - Robert Israel, Jan 24 2019

A269605 Number of length-n 0..7 arrays with no repeated value differing from the previous repeated value by one or less.

Original entry on oeis.org

8, 64, 504, 3962, 31024, 242226, 1886252, 14654952, 113629480, 879470154, 6796127732, 52443005888, 404170590152, 3111359345068, 23927329547328, 183840499514208, 1411335451447128, 10826702362761906, 82998453154738884
Offset: 1

Views

Author

R. H. Hardin, Mar 01 2016

Keywords

Comments

Column 7 of A269606.

Examples

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

Crossrefs

Cf. A269606.

Programs

  • Maple
    with(LinearAlgebra):
    T:= Matrix(72,72):
    for x from 0 to 7 do
      for v from 0 to 8 do
        i:= 1 + x + 8*v;
        for y in {$0..7} minus {x} do
          T[i,1+y+8*v]:= 1;
        od:
        if abs(x-v) > 1 or v=8 then T[i,1+x+8*x]:= 1 fi
    od od:
    u:= Vector([0$64,1$8]): v:= Vector(72,1):
    Tv[1]:= v:
    for n from 2 to 50 do Tv[n]:= T . Tv[n-1] od:
    seq(u^%T . Tv[n], n=1..50); # Robert Israel, Jan 24 2019

Formula

Empirical: a(n) = 31*a(n-1) -353*a(n-2) +1601*a(n-3) -435*a(n-4) -14505*a(n-5) +7118*a(n-6) +65542*a(n-7) +66279*a(n-8) +19971*a(n-9)
Empirical formula verified: see link. - Robert Israel, Jan 24 2019

A269607 Number of length-4 0..n arrays with no repeated value differing from the previous repeated value by one or less.

Original entry on oeis.org

8, 62, 222, 572, 1220, 2298, 3962, 6392, 9792, 14390, 20438, 28212, 38012, 50162, 65010, 82928, 104312, 129582, 159182, 193580, 233268, 278762, 330602, 389352, 455600, 529958, 613062, 705572, 808172, 921570, 1046498, 1183712, 1333992
Offset: 1

Views

Author

R. H. Hardin, Mar 01 2016

Keywords

Examples

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

Crossrefs

Row 4 of A269606.

Formula

Empirical: a(n) = n^4 + 4*n^3 + 4*n^2 - n.
Conjectures from Colin Barker, Jan 25 2019: (Start)
G.f.: 2*x*(4 + 11*x - 4*x^2 + x^3) / (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)

A269608 Number of length-5 0..n arrays with no repeated value differing from the previous repeated value by one or less.

Original entry on oeis.org

10, 154, 804, 2692, 7030, 15630, 31024, 56584, 96642, 156610, 243100, 364044, 528814, 748342, 1035240, 1403920, 1870714, 2453994, 3174292, 4054420, 5119590, 6397534, 7918624, 9715992, 11825650, 14286610, 17141004, 20434204, 24214942
Offset: 1

Views

Author

R. H. Hardin, Mar 01 2016

Keywords

Examples

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

Crossrefs

Row 5 of A269606.

Formula

Empirical: a(n) = n^5 + 5*n^4 + 7*n^3 - 4*n^2 + n.
Conjectures from Colin Barker, Jan 25 2019: (Start)
G.f.: 2*x*(5 + 47*x + 15*x^2 - 11*x^3 + 4*x^4) / (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)

A269609 Number of length-6 0..n arrays with no repeated value differing from the previous repeated value by one or less.

Original entry on oeis.org

12, 376, 2878, 12570, 40288, 105892, 242226, 499798, 952180, 1702128, 2888422, 4693426, 7351368, 11157340, 16477018, 23757102, 33536476, 46458088, 63281550, 84896458, 112336432, 146793876, 189635458, 242418310, 306906948, 385090912
Offset: 1

Views

Author

R. H. Hardin, Mar 01 2016

Keywords

Examples

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

Crossrefs

Row 6 of A269606.

Formula

Empirical: a(n) = n^6 + 6*n^5 + 11*n^4 - 8*n^3 + n^2 + 3*n - 2.
Conjectures from Colin Barker, Jan 25 2019: (Start)
G.f.: 2*x*(6 + 146*x + 249*x^2 - 50*x^3 - 2*x^4 + 12*x^5 - x^6) / (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)

A269610 Number of length-7 0..n arrays with no repeated value differing from the previous repeated value by one or less.

Original entry on oeis.org

14, 902, 10192, 58280, 229754, 714874, 1886252, 4405772, 9366790, 18476654, 34284584, 60459952, 102126002, 166254050, 262123204, 401850644, 600997502, 879255382, 1261218560, 1777246904, 2464424554, 3367619402, 4540648412
Offset: 1

Views

Author

R. H. Hardin, Mar 01 2016

Keywords

Examples

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

Crossrefs

Row 7 of A269606.

Formula

Empirical: a(n) = n^7 + 7*n^6 + 16*n^5 - 12*n^4 - 5*n^3 + 18*n^2 - 15*n + 4.
Conjectures from Colin Barker, Jan 25 2019: (Start)
G.f.: 2*x*(7 + 395*x + 1684*x^2 + 608*x^3 - 321*x^4 + 143*x^5 + 6*x^6 - 2*x^7) / (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 1-10 of 10 results.