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.

A252532 T(n,k)=Number of (n+2)X(k+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 0 2 3 6 or 7 and every 3X3 column and antidiagonal sum not equal to 0 2 3 6 or 7.

Original entry on oeis.org

750, 730, 595, 621, 337, 460, 719, 341, 334, 535, 778, 462, 466, 426, 546, 932, 706, 626, 610, 676, 649, 1200, 1000, 1120, 790, 1114, 964, 823, 1498, 1468, 1760, 1592, 1676, 1748, 1344, 1036, 1968, 2420, 2404, 2440, 4420, 2504, 2332, 2312, 1328, 2708, 3480
Offset: 1

Views

Author

R. H. Hardin, Dec 18 2014

Keywords

Comments

Table starts
..750..730..621...719...778....932...1200....1498....1968....2708.....3473
..595..337..341...462...706...1000...1468....2420....3480....5240.....8872
..460..334..466...626..1120...1760...2404....4304....6832....9416....16864
..535..426..610...790..1592...2440...3160....6368....9760...12640....25472
..546..676.1114..1676..4420...7184..11456...31136...50560...83840...232192
..649..964.1748..2504..7136..13184..19232...54656..102272..150656...427520
..823.1344.2332..3160.10720..18656..25280...85760..149248..202240...686080
.1036.2312.4244..6704.30752..54464..91648..433664..763904.1341440..6471680
.1328.3336.6760.10016.49792.101888.153856..760832.1580032.2410496.11886592
.1756.4800.9112.12640.77696.145792.202240.1243136.2332672.3235840.19890176

Examples

			Some solutions for n=4 k=4
..2..2..3..2..2..3....1..1..0..1..1..0....3..2..2..3..2..2....0..2..1..0..1..1
..3..2..2..3..2..2....2..0..0..3..0..0....3..0..3..3..0..3....0..2..0..0..3..3
..3..0..3..3..0..3....1..0..1..1..0..1....2..2..3..2..2..3....1..1..0..1..1..0
..2..2..3..2..2..3....1..1..0..1..1..0....3..2..2..3..2..2....0..1..1..0..1..1
..3..2..2..3..2..2....3..0..0..2..0..0....3..1..3..3..0..3....0..3..0..0..3..0
..0..0..3..3..1..3....1..0..1..1..0..1....2..2..3..2..2..3....1..1..0..1..1..0
		

Formula

Empirical for column k:
k=1: a(n) = 4*a(n-3) -3*a(n-6) -4*a(n-9) +4*a(n-12) for n>23
k=2: a(n) = 6*a(n-3) -8*a(n-6) for n>10
k=3: a(n) = 6*a(n-3) -8*a(n-6) for n>8
k=4: a(n) = 4*a(n-3) for n>5
k=5: a(n) = 12*a(n-3) -32*a(n-6) for n>8
k=6: a(n) = 12*a(n-3) -32*a(n-6) for n>8
k=7: a(n) = 8*a(n-3) for n>5
Empirical for row n:
n=1: a(n) = 4*a(n-3) -3*a(n-6) -4*a(n-9) +4*a(n-12) for n>39
n=2: a(n) = 6*a(n-3) -8*a(n-6) for n>10
n=3: a(n) = 6*a(n-3) -8*a(n-6) for n>8
n=4: a(n) = 4*a(n-3) for n>5
n=5: a(n) = 12*a(n-3) -32*a(n-6) for n>8
n=6: a(n) = 12*a(n-3) -32*a(n-6) for n>8
n=7: a(n) = 8*a(n-3) for n>5