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.

Previous Showing 11-17 of 17 results.

A224050 T(n,k)=Number of nXk 0..3 arrays with rows and columns unimodal and antidiagonals nondecreasing.

Original entry on oeis.org

4, 16, 16, 50, 160, 50, 130, 984, 984, 130, 296, 4580, 9731, 4580, 296, 610, 17723, 67585, 67585, 17723, 610, 1163, 59792, 376734, 638996, 376734, 59792, 1163, 2083, 180821, 1801402, 4646480, 4646480, 1801402, 180821, 2083, 3544, 499357, 7655477
Offset: 1

Views

Author

R. H. Hardin Apr 01 2013

Keywords

Comments

Table starts
....4......16........50.........130..........296...........610...........1163
...16.....160.......984........4580........17723.........59792.........180821
...50.....984......9731.......67585.......376734.......1801402........7655477
..130....4580.....67585......638996......4646480......28403642......153482649
..296...17723....376734.....4646480.....41991129.....310514900.....1999959111
..610...59792...1801402....28403642....310514900....2701569493....20096076442
.1163..180821...7655477...153482649...1999959111...20096076442...169750613182
.2083..499357..29502561...753824187..11666303576..133729094355..1265415997425
.3544.1276595.104437965..3415377142..63064614327..821109158656..8609328529478
.5776.3053471.342818189.14392067725.319676018383.4743773544158.54810160645347

Examples

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

Crossrefs

Column 1 is A223659
Column 2 is A224058

Formula

Empirical: columns k=1..5 are polynomials of degree 6*k for n>0,0,1,3,5

A224064 T(n,k)=Number of nXk 0..3 arrays with rows, columns and antidiagonals unimodal and diagonals nondecreasing.

Original entry on oeis.org

4, 16, 16, 50, 160, 50, 130, 984, 984, 130, 296, 4580, 8854, 4580, 296, 610, 17723, 58814, 58814, 17723, 610, 1163, 59792, 324702, 506513, 324702, 59792, 1163, 2083, 180821, 1557606, 3509115, 3509115, 1557606, 180821, 2083, 3544, 499357, 6643979
Offset: 1

Views

Author

R. H. Hardin Mar 30 2013

Keywords

Comments

Table starts
....4......16........50.........130..........296..........610.........1163
...16.....160.......984........4580........17723........59792.......180821
...50.....984......8854.......58814.......324702......1557606......6643979
..130....4580.....58814......506513......3509115.....21167501....114643788
..296...17723....324702.....3509115.....28682690....200974242...1274747540
..610...59792...1557606....21167501....200974242...1573171210..11060805360
.1163..180821...6643979...114643788...1274747540..11060805360..83942450048
.2083..499357..25596389...564290412...7460451193..72498474377.591725806925
.3544.1276595..90177585..2542634801..40485099654.448019196499
.5776.3053471.293585050.10557558941.203984697906

Examples

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

Crossrefs

Column 1 is A223659

Formula

Empirical: columns k=1..5 are polynomials of degree 6*k for n>0,0,3,7,11

A224123 T(n,k)=Number of nXk 0..3 arrays with row sums nondecreasing and column sums unimodal.

Original entry on oeis.org

4, 16, 10, 50, 150, 20, 130, 1747, 1080, 35, 296, 16782, 47059, 6627, 56, 610, 140210, 1703178, 1070499, 36552, 84, 1163, 1050460, 53355889, 145901795, 21632718, 187000, 120, 2083, 7227405, 1491827492, 17292618579, 11066001160, 400993828
Offset: 1

Views

Author

R. H. Hardin Mar 31 2013

Keywords

Comments

Table starts
...4......16.........50..........130...........296...........610
..10.....150.......1747........16782........140210.......1050460
..20....1080......47059......1703178......53355889....1491827492
..35....6627....1070499....145901795...17292618579.1830213565657
..56...36552...21632718..11066001160.4964366292229
..84..187000..400993828.766386005577
.120..905440.6962188526
.165.4206453
.220

Examples

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

Crossrefs

Column 1 is A000292(n+1)
Column 2 is A223069
Row 1 is A223659

A223756 Number of n X 2 0..3 arrays with rows, antidiagonals and columns unimodal.

Original entry on oeis.org

16, 256, 2500, 16900, 87616, 372100, 1352569, 4338889, 12559936, 33362176, 82373776, 190992400, 419266576, 877225924, 1759047481, 3396208729, 6338070544, 11471266816, 20192978404, 34657779556, 58123423744, 95427859396
Offset: 1

Views

Author

R. H. Hardin, Mar 27 2013

Keywords

Comments

Column 2 of A223762.

Examples

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

Formula

Empirical: a(n) = (1/518400)*n^12 + (1/17280)*n^11 + (91/103680)*n^10 + (71/8640)*n^9 + (9101/172800)*n^8 + (457/1920)*n^7 + (81397/103680)*n^6 + (497/270)*n^5 + (203687/64800)*n^4 + (1933/540)*n^3 + (2533/720)*n^2 + (11/6)*n + 1.
a(n) = A223659(n)^2. - Mark van Hoeij, May 14 2013
Conjectures from Colin Barker, Feb 19 2018: (Start)
G.f.: x*(16 + 48*x + 420*x^2 - 208*x^3 + 1140*x^4 - 1260*x^5 + 1401*x^6 - 1044*x^7 + 597*x^8 - 244*x^9 + 69*x^10 - 12*x^11 + x^12) / (1 - x)^13.
a(n) = 13*a(n-1) - 78*a(n-2) + 286*a(n-3) - 715*a(n-4) + 1287*a(n-5) - 1716*a(n-6) + 1716*a(n-7) - 1287*a(n-8) + 715*a(n-9) - 286*a(n-10) + 78*a(n-11) - 13*a(n-12) + a(n-13) for n>13.
(End)

A223811 T(n,k)=Number of nXk 0..3 arrays with rows, columns, diagonals and antidiagonals unimodal.

Original entry on oeis.org

4, 16, 16, 50, 256, 50, 130, 2500, 2500, 130, 296, 16900, 58806, 16900, 296, 610, 87616, 825896, 825896, 87616, 610, 1163, 372100, 8165133, 20847008, 8165133, 372100, 1163, 2083, 1352569, 62305953, 342521725, 342521725, 62305953, 1352569, 2083
Offset: 1

Views

Author

R. H. Hardin Mar 27 2013

Keywords

Comments

Table starts
....4.......16..........50............130.............296.............610
...16......256........2500..........16900...........87616..........372100
...50.....2500.......58806.........825896.........8165133........62305953
..130....16900......825896.......20847008.......342521725......4146732319
..296....87616.....8165133......342521725......8597979566....151474085262
..610...372100....62305953.....4146732319....151474085262...3678996027680
.1163..1352569...388531932....39816673636...2058985931297..66795003874023
.2083..4338889..2057610878...317796753758..22901512677629.975436194200049
.3544.12559936..9513089522..2176384736806.216485354275124
.5776.33362176.39201336756.13081738670880

Examples

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

Crossrefs

Column 1 is A223659
Column 2 is A223756

Formula

Empirical: columns k=1..5 are polynomials of degree 6*k for n>0,0,0,8,15

A279006 Alternating Jacobsthal triangle read by rows (second version).

Original entry on oeis.org

1, 1, 1, 1, 0, 1, 1, -1, 1, 1, 1, -2, 2, 0, 1, 1, -3, 4, -2, 1, 1, 1, -4, 7, -6, 3, 0, 1, 1, -5, 11, -13, 9, -3, 1, 1, 1, -6, 16, -24, 22, -12, 4, 0, 1, 1, -7, 22, -40, 46, -34, 16, -4, 1, 1, 1, -8, 29, -62, 86, -80, 50, -20, 5, 0, 1, 1, -9, 37, -91, 148, -166, 130, -70, 25, -5, 1, 1
Offset: 0

Views

Author

N. J. A. Sloane, Dec 07 2016

Keywords

Examples

			Triangle begins:
  1,
  1,   1,
  1,   0,   1,
  1,  -1,   1,   1,
  1,  -2,   2,   0,   1,
  1,  -3,   4,  -2,   1,   1,
  1,  -4,   7,  -6,   3,   0,   1,
  1,  -5,  11, -13,   9,  -3,   1,   1,
  1,  -6,  16, -24,  22, -12,   4,   0,   1,
  ...
		

Crossrefs

See A112468, A112555 and A108561 for other versions.

Programs

  • Maple
    T := (n, k) -> local j; add((-1)^j*binomial(n-k-1+j, j), j = 0..k):
    seq(print(seq(T(n, k), k = 0..n)), n = 0..9);  # Peter Luschny, Aug 30 2024
  • Mathematica
    T[i_, i_] = T[, 0] = 1; T[i, j_] := T[i, j] = T[i-1, j] - T[i-1, j-1];
    Table[T[i, j], {i, 0, 11}, {j, 0, i}] // Flatten (* Jean-François Alcover, Sep 06 2018 *)
    T[n_, k_] := 2^k*Hypergeometric2F1[-n, -k, -k, 1/2]; Table[T[n, k], {n, 0, 11}, {k, 0, n}]//Flatten (* Detlef Meya, Aug 30 2024 *)
  • PARI
    \\ using arxiv (3.1) and (3.7) formulas where A is A220074 and B is this sequence
    A(i, j) = if ((i < 0), 0, if (j==0, 1, A(i - 1, j - 1) - A(i - 1, j))); \\ A220074
    B(i, j) = A(i, i-j);
    tabl(nn) = for (i=0, nn, for (j=0, i, print1(B(i,j), ", ")); print()); \\ Michel Marcus, Jun 17 2017

Formula

T(i, j) = A220074(i, i-j). See (3.7) in arxiv link. - Michel Marcus, Jun 17 2017
T(n, k) = 2^k*hypergeom([-n, -k], [-k], 1/2). - Detlef Meya, Aug 30 2024

Extensions

More terms from Michel Marcus, Jun 17 2017

A224113 T(n,k)=Number of nXk 0..3 arrays with row sums and column sums unimodal.

Original entry on oeis.org

4, 16, 16, 50, 256, 50, 130, 3060, 3060, 130, 296, 29922, 141112, 29922, 296, 610, 252912, 5286827, 5286827, 252912, 610, 1163, 1912914, 169786856, 762031090, 169786856, 1912914, 1163, 2083, 13254601, 4837645361, 93991412090, 93991412090
Offset: 1

Views

Author

R. H. Hardin Mar 31 2013

Keywords

Comments

Table starts
....4........16............50..............130...............296
...16.......256..........3060............29922............252912
...50......3060........141112..........5286827.........169786856
..130.....29922.......5286827........762031090.......93991412090
..296....252912.....169786856......93991412090....44633436796823
..610...1912914....4837645361...10255460738958.18747100782890395
.1163..13254601..125243425246.1013220280453733
.2083..85563043.2997702534361
.3544.521069404
.5776

Examples

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

Crossrefs

Column 1 is A223659
Column 2 is A223660
Previous Showing 11-17 of 17 results.