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.

A156286 Triangle T(n, k) = (1/k^n)*Product_{j=1..n} ( (k-1)*(k+1)^j + 1 ), read by rows.

Original entry on oeis.org

1, 1, 10, 1, 140, 1419, 1, 5740, 242649, 3350536, 1, 700280, 165729267, 7853656384, 161827775045, 1, 255602200, 452606628177, 92036999164096, 6040221703554625, 193317016162131576, 1, 279628806800, 4943822199577371, 5392815929021041024, 1352701610289354714125, 132670761753844630766736, 6731905265314349384346775
Offset: 1

Views

Author

Roger L. Bagula, Feb 07 2009

Keywords

Examples

			Triangle begins as:
  1;
  1,     10;
  1,    140,      1419;
  1,   5740,    242649,    3350536;
  1, 700280, 165729267, 7853656384, 161827775045;
		

Crossrefs

Cf. A156173.

Programs

  • Magma
    A156286:= func< n,k | (&*[(k-1)*(k+1)^j + 1: j in [1..n]])/k^n >;
    [A156286(n,k): k in [1..n], n in [1..10]]; // G. C. Greubel, Jan 02 2022
    
  • Mathematica
    T[n_, k_]:= (1/k^n)*Product[(k-1)*(k+1)^j +1, {j,n}];
    Table[T[n, k], {n, 10}, {k, n}]//Flatten (* modified by G. C. Greubel, Jan 02 2022 *)
  • Sage
    def A156286(n,k): return (1/k^n)*product( (k-1)*(k+1)^j +1 for j in (1..n) )
    flatten([[A156286(n,k) for k in (1..n)] for n in (1..10)]) # G. C. Greubel, Jan 02 2022

Formula

T(n, k) = Product_{j=1..n} ( (k+1)^j - Sum_{i=0..k-1} (k+1)^i ).
T(n, k) = (1/k^n)*Product_{j=1..n} ( (k-1)*(k+1)^j + 1 ). - G. C. Greubel, Jan 02 2022

Extensions

Edited by G. C. Greubel, Jan 02 2022