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.

A130493 Triangle read by rows in which row n contains n! repeated n times.

Original entry on oeis.org

1, 2, 2, 6, 6, 6, 24, 24, 24, 24, 120, 120, 120, 120, 120, 720, 720, 720, 720, 720, 720, 5040, 5040, 5040, 5040, 5040, 5040, 5040, 40320, 40320, 40320, 40320, 40320, 40320, 40320, 40320, 362880, 362880, 362880, 362880, 362880, 362880, 362880, 362880, 362880
Offset: 1

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Author

Gary W. Adamson, May 31 2007

Keywords

Comments

Row sums = A001563: (1, 4, 18, 96, 600, 4320, ...). A130477(n,k) * A130478(n,k) = A130493(n,k). Example: take dot products of rows with equal numbers of terms in A130477 and A130478, (1, 3, 8, 12) dot (24, 8, 3, 2) = (24, 24, 24, 24).

Examples

			First few rows of the triangle:
   1;
   2,  2;
   6,  6,  6;
  24, 24, 24, 24;
  ...
		

Crossrefs

Programs

  • Mathematica
    Flatten[Table[Table[n!,{n}],{n,10}]] (* Harvey P. Dale, Dec 24 2014 *)
    Table[PadRight[{},n,n!],{n,10}]//Flatten (* Harvey P. Dale, Jul 04 2022 *)
  • Python
    from math import isqrt
    from sympy import factorial
    def A130493(n): return factorial((m:=isqrt(k:=n<<1))+(k>m*(m+1))) # Chai Wah Wu, Nov 07 2024

Formula

Triangle, n! repeated n times per row.

Extensions

More terms from Sean A. Irvine, Jul 19 2022