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 1-6 of 6 results.

A067304 Generalized Catalan triangle A067298 with row reversion.

Original entry on oeis.org

1, 2, 1, 9, 5, 4, 64, 36, 32, 28, 584, 328, 300, 284, 256, 6144, 3440, 3184, 3072, 2960, 2704, 70576, 39408, 36704, 35680, 34896, 33872, 31168, 859520, 478912, 447744, 436928, 429760, 422592, 411776, 380608, 10909440, 6068480, 5687872, 5563200, 5487488, 5421952, 5346240, 5221568, 4840960
Offset: 0

Views

Author

Wolfdieter Lang, Feb 05 2002

Keywords

Comments

Identity for each row n >= 1: T(n, m) + T(n, n-m+1) = A067297(n+1) (convolution of generalized Catalan numbers) for every m = 1..floor((n+1)/2). E.g., T(2*k+1, k+1) = A067297(2*(k+1))/2.

Examples

			Triangle begins:
    1;
    2,   1;
    9,   5,   4;
   64,  36,  32,  28;
  584, 328, 300, 284, 256;
  ...
n=3: T(3, 0) = 64 = 36+28 = 32+32.
		

Crossrefs

The columns give for m=0..4: A067297 (diagonals of A067298), A067305, A067306, A067307, A067308.
Cf. A067302 (row sums), A067323 (corresponding triangle for ordinary Catalan numbers).

Formula

T(n, m) = A067298(n, n-m), n >= m >= 0, otherwise 0.
G.f. for column m >= 1 (without leading zeros): (2^(2*ceiling(m/2))*p(m, y)*(y^3)/(1+y)^4, where y = y(x) = c(4*x), with c(x) = g.f. of A000108 (Catalan) and the row polynomials p(n, y) = Sum_{k=0..n} A067329(n, k)*y^k, n >= 1. For m = 0: ((y*(3+y))^2)/(1+y)^4 with y = y(x) = c(4*x) (see A067297).

Extensions

More terms from Jinyuan Wang, Apr 20 2025

A067302 Row sums of triangle A067298 and of A067304.

Original entry on oeis.org

1, 3, 18, 160, 1752, 21504, 282304, 3867840, 54547200, 785255680, 11478167040, 169748686848, 2533556365312, 38094656593920, 576271774875648, 8761529890717696, 133776598692003840, 2050020136793604096
Offset: 0

Views

Author

Wolfdieter Lang, Feb 05 2002

Keywords

Formula

a(n)=sum(A067298(n, m), m=0..n ).
Bisection: a(2*k)= (k+1)*A067297(2*k)=: A067303(k), a(2*k+1)= (2*k+3)*A067297(2*k+1)/2 =: A067322(k), k>=0.
G.f.: ge(x^2) + x*go(x^2) with ge(x) g.f. of A067303 and go(x) g.f. of A067322.

A067300 One third of third column of triangle A067298.

Original entry on oeis.org

3, 12, 100, 1024, 11632, 140864, 1782080, 23273984, 311407360, 4246776832, 58812433408, 824868814848, 11692779565056, 167254617440256, 2411126992093184, 34994856661483520, 510941885186637824
Offset: 0

Views

Author

Wolfdieter Lang, Feb 05 2002

Keywords

Crossrefs

Cf. A067299 (second column), 8*A067301 (fourth column).

Formula

a(n)=A067298(n+2, 2)/3.
G.f.: ((1-4*x)*c(4*x)+2)/(1-2*x*c(4*x))^2, with c(x) is g.f. for A000108 (Catalan).

A067299 Second column of triangle A067298.

Original entry on oeis.org

2, 5, 32, 284, 2960, 33872, 411776, 5221568, 68299520, 914858240, 12486496256, 173031701504, 2428066058240, 34432752275456, 492697174507520, 7104716644990976, 103142445617709056, 1506248913346691072
Offset: 0

Views

Author

Wolfdieter Lang, Feb 05 2002

Keywords

Crossrefs

Cf. A064340 (first column), A067300 (third column).

Formula

a(n)=A067298(n+1, 1).
G.f.: ((1+x)*c(2, 2; x)-1)/x, with c(2, 2; x) := (1-3*x*c(4*x))/(1-2*x*c(4*x))^2 g.f. for A064340 and c(x) is g.f. for A000108 (Catalan).
G.f.: (2+x + 12*x*(1+x)*c(4*x))/(1+2*x)^2, where c(x) is g.f. for A000108 (Catalan). - Wolfdieter Lang, May 05 2006.
Conjecture: n*(17*n-7)*a(n) +2*(-119*n^2+270*n-96)*a(n-1) -16*(17*n+10)*(2*n-3)*a(n-2)=0. - R. J. Mathar, Jul 21 2016

A067301 One eighth of fourth column of triangle A067298.

Original entry on oeis.org

8, 41, 398, 4460, 53720, 677744, 8836832, 118109888, 1609484672, 22276767488, 312305704448, 4425515174912, 63285369657344, 912105965121536, 13235652537933824, 193215065765888000, 2835518953336438784
Offset: 0

Views

Author

Wolfdieter Lang, Feb 05 2002

Keywords

Crossrefs

Cf. 3*A067300 (third column).

Formula

a(n) = A067298(n+3, 3)/8.
G.f.: ((-3+37*x)+(3+15*x-84*x^2)*c(4*x))/(8*x*(1-2*x*c(4*x))^2), with c(x) is g.f. for A000108 (Catalan).

A064340 Generalized Catalan numbers C(2,2; n).

Original entry on oeis.org

1, 1, 4, 28, 256, 2704, 31168, 380608, 4840960, 63458560, 851399680, 11635096576, 161396604928, 2266669453312, 32166082822144, 460531091685376, 6644185553305600, 96498260064403456, 1409750653282287616, 20702370737659052032, 305428492830594039808
Offset: 0

Views

Author

Wolfdieter Lang, Oct 12 2001

Keywords

Comments

See triangle A064879 with columns m built from C(m,m; n), m >= 0, also for Derrida et al. and Liggett references.

Crossrefs

Cf. A000108 (Catalan as C(1,1; n)), A064879, A067298.

Programs

  • PARI
    my(x='x+O('x^30)); Vec((1+(13-3*sqrt(1-16*x))*x/2)/(1+2*x)^2) \\ Jinyuan Wang, Apr 20 2025

Formula

a(n) = ((4^(n-1))/(n-1))*Sum_{m=0..n-2} (m+1)*(m+2)*binomial(2*(n-2)-m, n-2-m)/2^(m+1), n >= 2, a(0) = a(1) = 1.
G.f.: (1-3*x*c(4*x))/(1-2*x*c(4*x))^2 = c(4*x)*(3+c(4*x))/(1+c(4*x))^2 = (1+5*x+3*c(4*x)*(2*x)^2)/(1+2*x)^2 with c(x) = A(x) g.f. of Catalan numbers A000108.
(-n+1)*a(n) + 2*(7*n-20)*a(n-1) + 16*(2*n-3)*a(n-2) = 0. - R. J. Mathar, Aug 09 2017
Showing 1-6 of 6 results.