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.

A231137 T(n,k)=Number of (n+1)X(k+1) black-square subarrays of 0..2 arrays with no element equal to a strict majority of its diagonal and antidiagonal neighbors, with values 0..2 introduced in row major order.

Original entry on oeis.org

1, 2, 2, 6, 9, 6, 16, 40, 40, 16, 44, 182, 308, 182, 44, 120, 808, 2260, 2260, 808, 120, 328, 3688, 16812, 27171, 16812, 3688, 328, 896, 16368, 124644, 336004, 336004, 124644, 16368, 896, 2448, 74728, 924900, 4066129, 6794904, 4066129, 924900, 74728, 2448
Offset: 1

Views

Author

R. H. Hardin, Nov 04 2013

Keywords

Comments

Table starts
..1...2.....6.....16......44.......120........328.........896..........2448
..2...9....40....182.....808......3688......16368.......74728........331648
..6..40...308...2260...16812....124644.....924900.....6862052......50913012
.16.182..2260..27171..336004...4066129...50257244...608468617....7520563372
.44.808.16812.336004.6794904.137063228.2766762720.55844298404.1127200291672

Examples

			Some solutions for n=2 k=4
..x..0..x..1..x....x..0..x..1..x....x..0..x..0..x....x..0..x..1..x
..2..x..0..x..1....1..x..0..x..2....1..x..2..x..0....2..x..0..x..2
..x..0..x..2..x....x..0..x..1..x....x..1..x..2..x....x..1..x..1..x
		

Crossrefs

Column 1 is A002605
Column 3 is A231126
Column 5 is A231128
Column 7 is A231130

Formula

Empirical for column k:
k=1: a(n) = 2*a(n-1) +2*a(n-2)
k=2: a(n) = 22*a(n-2) -36*a(n-4) +16*a(n-6)
k=3: [order 8]
k=4: [order 18, even terms]
k=5: [order 34]
k=6: [order 90, even terms]