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.

A126450 Triangle, read by rows, where T(n,k) = C( C(n+2,3) - C(k+2,3) + 1, n-k) for n>=k>=0.

Original entry on oeis.org

1, 2, 1, 10, 4, 1, 165, 45, 7, 1, 5985, 1140, 136, 11, 1, 376992, 52360, 4960, 325, 16, 1, 36288252, 3819816, 292825, 16215, 666, 22, 1, 4935847320, 406481544, 25621596, 1215450, 43680, 1225, 29, 1, 899749479915, 59487568920, 3127595016, 128164707
Offset: 0

Views

Author

Paul D. Hanna, Dec 27 2006

Keywords

Comments

Examples

			Formula: T(n,k) = C( C(n+2,3) - C(k+2,3) + 1, n-k) is illustrated by:
T(n=4,k=1) = C( C(6,3) - C(3,3) + 1, n-k) = C(20,3) = 1140;
T(n=4,k=2) = C( C(6,3) - C(4,3) + 1, n-k) = C(17,2) = 136;
T(n=5,k=2) = C( C(7,3) - C(4,3) + 1, n-k) = C(32,3) = 4960.
Triangle begins:
1;
2, 1;
10, 4, 1;
165, 45, 7, 1;
5985, 1140, 136, 11, 1;
376992, 52360, 4960, 325, 16, 1;
36288252, 3819816, 292825, 16215, 666, 22, 1;
4935847320, 406481544, 25621596, 1215450, 43680, 1225, 29, 1; ...
		

Crossrefs

Columns: A126451, A126452; A126453 (row sums); variants: A126445, A126454, A126457, A107867.

Programs

  • PARI
    T(n,k)=binomial(n*(n+1)*(n+2)/3!-k*(k+1)*(k+2)/3!+1, n-k)

Formula

T(n,k) = C( n*(n+1)*(n+2)/3! - k*(k+1)*(k+2)/3! + 1, n-k) for n>=k>=0.

A126446 Column 0 of triangle A126445; a(n) = binomial( binomial(n+2,3), n).

Original entry on oeis.org

1, 1, 6, 120, 4845, 324632, 32468436, 4529365776, 840261910995, 200063149171380, 59473554359599446, 21592914273609648996, 9403538945961296957821, 4838670732821812768919800, 2904538537066424425438417800
Offset: 0

Views

Author

Paul D. Hanna, Dec 27 2006

Keywords

Crossrefs

Programs

  • Magma
    [(Binomial(Binomial(n+3, n), n+1)): n in [-1..20]]; // Vincenzo Librandi, Mar 04 2018
  • Mathematica
    Table[Binomial[n (n + 1) (n + 2) / 3!, n], {n, 0, 20}] (* Vincenzo Librandi, Mar 04 2018 *)
  • PARI
    a(n)=binomial(n*(n+1)*(n+2)/3!, n)
    
  • Sage
    [(binomial(binomial(n+3,n),n+1)) for n in range(-1, 12)] # Zerinvary Lajos, Nov 30 2009
    

A126452 Column 1 of triangle A126450; a(n) = C( C(n+3,3), n).

Original entry on oeis.org

1, 4, 45, 1140, 52360, 3819816, 406481544, 59487568920, 11468588169060, 2818651865383860, 860587163078645431, 319667046321630491484, 141992594868360194121800, 74339194732961502662043600
Offset: 0

Views

Author

Paul D. Hanna, Dec 27 2006

Keywords

Crossrefs

Programs

  • Mathematica
    Table[Binomial[Binomial[n+3,3],n],{n,0,20}] (* Harvey P. Dale, Oct 09 2014 *)
  • PARI
    a(n)=binomial((n+1)*(n+2)*(n+3)/3!, n)

A126455 Column 0 of triangle A126454; a(n) = C( C(n+2,3) + 2, n).

Original entry on oeis.org

1, 3, 15, 220, 7315, 435897, 40475358, 5373200880, 962889794295, 223581013518060, 65230517839369311, 23345156728397937888, 10052806195411162278095, 5126493560257678027274800
Offset: 0

Views

Author

Paul D. Hanna, Dec 27 2006

Keywords

Crossrefs

Programs

  • Mathematica
    Table[Binomial[Binomial[n+2,3]+2,n],{n,0,20}] (* Harvey P. Dale, Dec 08 2018 *)
  • PARI
    a(n)=binomial(n*(n+1)*(n+2)/3!+2, n)

A126458 Column 0 of triangle A126457; a(n) = C( C(n+2,3) + 3, n).

Original entry on oeis.org

1, 4, 21, 286, 8855, 501942, 45057474, 5843355957, 1029873432159, 236236542585120, 68292983465630781, 24268885951464043344, 10392619362579990298763, 5276256293478688846049120
Offset: 0

Views

Author

Paul D. Hanna, Dec 27 2006

Keywords

Crossrefs

Programs

  • PARI
    a(n)=binomial(n*(n+1)*(n+2)/3!+3, n)

A126453 Row sums of triangle A126450: a(n) = Sum_{k=0..n} C( C(n+2,3) - C(k+2,3) + 1, n-k).

Original entry on oeis.org

1, 3, 15, 218, 7273, 434654, 40417797, 5369210845, 962496995941, 223528473482380, 65221305164439085, 23343099723197369886, 10052235133879615066675, 5126300310101866339983229
Offset: 0

Views

Author

Paul D. Hanna, Dec 27 2006

Keywords

Crossrefs

Programs

  • PARI
    a(n)=sum(k=0,n,binomial(binomial(n+2,3)-binomial(k+2,3)+1, n-k))
Showing 1-6 of 6 results.