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 1-5 of 5 results.

A329096 Row sums of A329057.

Original entry on oeis.org

1, 2, 8, 47, 374, 3852, 49398, 762785, 13805702, 286796072, 6727496456, 175903776622, 5073226515772, 160000741383368, 5478160073933490, 202366832844684645, 8022796547785815878, 339769654607776375824, 15309183806159727889536, 731253261602981693567090, 36909816019024064633444820
Offset: 0

Views

Author

Stefano Spezia, Nov 04 2019

Keywords

Crossrefs

Programs

  • Mathematica
    Table[(Binomial[2n,n]Hypergeometric2F1[1,-n,-2n,1+n])/(1+n),{n,0,20}]
  • PARI
    {a(n) = sum(k=0,n, binomial(2*n-k, n) * (n+1)^(k-1) )}
    for(n=0,25,print1(a(n),", ")) \\ Paul D. Hanna, Sep 12 2024
    
  • PARI
    {a(n) = my(C = (1 - sqrt(1-4*x +x^2*O(x^n)))/2);
    (1/(n+1)) * polcoef( C'/(1 - (n+1)*C), n)}
    for(n=0,25,print1(a(n),", ")) \\ Paul D. Hanna, Sep 12 2024

Formula

a(n) = binomial(2*n, n)*2F1([1, -n], [-2*n], 1 + n)/(1 + n), where 2F1 is the hypergeometric function.
a(n) ~ exp(2) * n^(n-1). - Vaclav Kotesovec, Nov 04 2019
From Paul D. Hanna, Sep 12 2024: (Start)
a(n) = Sum_{k=0..n} binomial(2*n-k, n) * (n+1)^(k-1).
a(n) = (1/(n+1)) * [x^n] C(x)'/(1 - (n+1)*C(x)) for n >= 0 where C(x) = (1 - sqrt(1-4*x))/2 is the g.f. of the Catalan numbers (A000108). (End)

A329058 2-parking triangle T(r, i, 2) read by rows: T(r, i, k) = (r + 1)^(i-1)*binomial(k*(r + 1) + r - i - 1, r - i) with k = 2 and 0 <= i <= r.

Original entry on oeis.org

1, 2, 1, 7, 6, 3, 30, 36, 32, 16, 143, 220, 275, 250, 125, 728, 1365, 2184, 2808, 2592, 1296, 3876, 8568, 16660, 27440, 36015, 33614, 16807, 21318, 54264, 124032, 248064, 417792, 557056, 524288, 262144, 120175, 346104, 908523, 2133054, 4363065, 7479540, 10097379, 9565938, 4782969
Offset: 0

Views

Author

Stefano Spezia, Nov 02 2019

Keywords

Comments

The k-parking numbers interpolate between the generalized Fuss-Catalan numbers and the number of parking functions (see Yip).

Examples

			r/i|   0   1   2   3   4
————————————————————————
0  |   1
1  |   2   1
2  |   7   6   3
3  |  30  36  32  16
4  | 143 220 275 250 125
		

Crossrefs

Programs

  • Mathematica
    T[r_, i_,k_] := (r + 1)^(i-1)*Binomial[k*(r + 1) + r - i - 1, r - i]; Flatten[Table[T[r,i,2],{r,0,9},{i,0,r}]]

Formula

T(r, i, k) = (r + 1)^(i-1)*binomial(k*(r + 1) + r - i - 1, r - i).
T(r, 0, 2) = A006013(r).
T(r, r, 2) = A000272(r + 1).

A329059 3-parking triangle T(r, i, 3) read by rows: T(r, i, k) = (r + 1)^(i-1)*binomial(k*(r + 1) + r - i - 1, r - i) with k = 3 and 0 <= i <= r.

Original entry on oeis.org

1, 3, 1, 15, 9, 3, 91, 78, 48, 16, 612, 680, 600, 375, 125, 4389, 5985, 6840, 6156, 3888, 1296, 32890, 53130, 74382, 86779, 79233, 50421, 16807, 254475, 475020, 786240, 1123200, 1331200, 1228800, 786432, 262144, 2017356, 4272048, 8155728, 13762791, 19978245, 23973894, 22320522, 14348907, 4782969
Offset: 0

Views

Author

Stefano Spezia, Nov 03 2019

Keywords

Comments

The k-parking numbers interpolate between the generalized Fuss-Catalan numbers and the number of parking functions (see Yip).

Examples

			r/i|      0      1      2      3      4
———————————————————————————————————————
0  |      1
1  |      3      1
2  |     15      9      3
3  |     91     78     48     16
4  |    612    680    600    375    125
...
		

Crossrefs

Programs

  • Mathematica
    T[r_, i_,k_] := (r + 1)^(i-1)*Binomial[k*(r + 1) + r - i - 1, r - i]; Flatten[Table[T[r,i,3],{r,0,8},{i,0,r}]]

Formula

T(r, i, k) = (r + 1)^(i-1)*binomial(k*(r + 1) + r - i - 1, r - i).
T(r, 0, 3) = A006632(r + 1).
T(r, r, 3) = A000272(r + 1).

A329060 4-parking triangle T(r, i, 4) read by rows: T(r, i, k) = (r + 1)^(i-1)*binomial(k*(r + 1) + r - i - 1, r - i) with k = 4 and 0 <= i <= r.

Original entry on oeis.org

1, 4, 1, 26, 12, 3, 204, 136, 64, 16, 1771, 1540, 1050, 500, 125, 16380, 17550, 15600, 10800, 5184, 1296, 158224, 201376, 220255, 198940, 139258, 67228, 16807, 1577532, 2324784, 3015936, 3351040, 3063808, 2162688, 1048576, 262144, 16112057, 26978328, 40467492, 53298648, 59960979, 55348596, 39326634, 19131876, 4782969
Offset: 0

Views

Author

Stefano Spezia, Nov 03 2019

Keywords

Comments

The k-parking numbers interpolate between the generalized Fuss-Catalan numbers and the number of parking functions (see Yip).

Examples

			r/i|    0      1      2      3      4
—————————————————————————————————————
0  |    1
1  |    4      1
2  |   26     12      3
3  |  204    136     64     16
4  | 1771   1540   1050    500    125
...
		

Crossrefs

Programs

  • Mathematica
    T[r_, i_, k_] := (r + 1)^(i-1)*Binomial[k*(r + 1) + r - i - 1, r - i]; Flatten[Table[T[r,i,4],{r,0,8},{i,0,r}]]

Formula

T(r, i, k) = (r + 1)^(i-1)*binomial(k*(r + 1) + r - i - 1, r - i).
T(r, 0, 4) = A118971(r).
T(r, r, 4) = A000272(r + 1).

A331799 Normalized volume of the Caracol flow polytope. Also equal to the number of "unified diagrams" of the Caracol graph (see Section 4.3 and Section 5 in Benedetti et al. reference).

Original entry on oeis.org

1, 3, 32, 625, 18144, 705894, 34603008, 2051893701, 143000000000, 11464341673642, 1039964049506304, 105353940923859082, 11793014101010071552, 1445828316284179687500, 192713711798795989155840, 27750747808814680091687085, 4293818865468117678192721920
Offset: 1

Views

Author

Alejandro H. Morales, Jan 26 2020

Keywords

Examples

			For n=3, a(3) = 32 = 2*(3+1)^2.
		

Crossrefs

Programs

  • Maple
    a:=proc(n)
      return (1/n)*binomial(2*n-2,n-1)*(n+1)^(n-1);
    end proc:
  • Mathematica
    Array[(1/#) Binomial[2 # - 2, # - 1] (# + 1)^(# - 1) &, 17] (* Michael De Vlieger, Jan 28 2020 *)

Formula

a(n) = A000108(n-1)*A000272(n+1).
a(n) = (1/n)*binomial(2*n-2,n-1)*(n+1)^(n-1).
a(n) = Sum_{i>=0..n-1} binomial(2*n-2,i)*A329057(n-1,i).
Showing 1-5 of 5 results.