[go: up one dir, main page]

login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A231131
T(n,k)=Number of (n+1)X(k+1) white-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
8
1, 2, 2, 6, 8, 6, 16, 40, 40, 16, 44, 176, 308, 176, 44, 120, 808, 2260, 2260, 808, 120, 328, 3584, 16812, 27664, 16812, 3584, 328, 896, 16368, 124644, 336004, 336004, 124644, 16368, 896, 2448, 72640, 924900, 4150352, 6794904, 4150352, 924900, 72640, 2448
OFFSET
1,2
COMMENTS
Table starts
..1...2.....6.....16......44.......120........328.........896..........2448
..2...8....40....176.....808......3584......16368.......72640........331648
..6..40...308...2260...16812....124644.....924900.....6862052......50913012
.16.176..2260..27664..336004...4150352...50257244...621150768....7520563372
.44.808.16812.336004.6794904.137063228.2766762720.55844298404.1127200291672
LINKS
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]
EXAMPLE
Some solutions for n=2 k=4
..0..x..1..x..1....0..x..0..x..1....0..x..1..x..0....0..x..0..x..1
..x..1..x..2..x....x..1..x..0..x....x..1..x..2..x....x..1..x..2..x
..2..x..2..x..1....2..x..1..x..1....0..x..0..x..0....0..x..2..x..1
CROSSREFS
Column 1 is A002605
Sequence in context: A306688 A092522 A116542 * A142243 A269722 A091441
KEYWORD
nonn,tabl
AUTHOR
R. H. Hardin, Nov 04 2013
STATUS
approved