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.

A255740 Square array read by antidiagonals upwards: T(n,1) = 1; for k > 1, T(n,k) = (n-1)*(n-2)^(A000120(k-1)-1) with n >= 1.

Original entry on oeis.org

1, 1, 0, 1, 1, 0, 1, 2, 1, 0, 1, 3, 2, 0, 0, 1, 4, 3, 2, 1, 0, 1, 5, 4, 6, 2, 0, 0, 1, 6, 5, 12, 3, 2, 0, 0, 1, 7, 6, 20, 4, 6, 2, 0, 0, 1, 8, 7, 30, 5, 12, 6, 2, 1, 0, 1, 9, 8, 42, 6, 20, 12, 12, 2, 0, 0, 1, 10, 9, 56, 7, 30, 20, 36, 3, 2, 0, 0, 1, 11, 10, 72, 8, 42, 30, 80, 4, 6, 2, 0, 0, 1, 12, 11, 90, 9, 56, 42, 150, 5, 12, 6, 2, 0, 0
Offset: 1

Views

Author

Omar E. Pol, Mar 05 2015

Keywords

Comments

The partial sums of row n give the n-th row of the square array A255741.

Examples

			The corner of the square array with the first 16 terms of the first 12 rows looks like this:
-------------------------------------------------------------------------
A000007: 1, 0, 0,  0, 0,  0,  0,   0, 0,  0,  0,   0,  0,   0,   0,    0
A255738: 1, 1, 1,  0, 1,  0,  0,   0  1,  0,  0,   0,  0,   0,   0,    0
A040000: 1, 2, 2,  2, 2,  2,  2,   2, 2,  2,  2,   2,  2,   2,   2,    2
A151787: 1, 3, 3,  6, 3,  6,  6,  12, 3,  6,  6,  12,  6,  12,  12,   24
A147582: 1, 4, 4, 12, 4, 12, 12,  36, 4, 12, 12,  36, 12,  36,  36,  108
A151789: 1, 5, 5, 20, 5, 20, 20,  80, 5, 20, 20,  80, 20,  80,  80,  320
A151779: 1, 6, 6, 30, 6, 30, 30, 150, 6, 30, 30, 150, 30, 150, 150,  750
A151791: 1, 7, 7, 42, 7, 42, 42, 252, 7, 42, 42, 252, 42, 252, 252, 1512
A151782: 1, 8, 8, 56, 8, 56, 56, 392, 8, 56, 56, 392, 56, 392, 392, 2744
A255743: 1, 9, 9, 72, 9, 72, 72, 576, 9, 72, 72, 576, 72, 576, 576, 4608
A255744: 1,10,10, 90,10, 90, 90, 810,10, 90, 90, 810, 90, 810, 810, 7290
A255745: 1,11,11,110,11,110,110,1100,11,110,110,1100,110,1100,1100,11000
...
		

Crossrefs

Column 1 is A000012.
Columns 2^k+1, for k >=0: A011477.
Columns 4, 6, 7, 10, 11, 13...: 0 together with A002378.

Programs

  • PARI
    tabl(nn) = {for (n=1, nn, for (k=1, nn, if (k==1, x = 1, x= (n-1)*(n-2)^(hammingweight(k-1)-1)); print1(x, ", ");); print(););} \\ Michel Marcus, Mar 15 2015

Formula

T(n,1) = 1; for k > 1, T(n,k) = (n-1)*(n-2)^(A000120(k-1)-1) with n >= 1.