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.

A243641 T(n,k)=Number of length n+2 0..k arrays with no three unequal elements in a row and new values 0..k introduced in 0..k order.

Original entry on oeis.org

4, 4, 8, 4, 9, 16, 4, 9, 21, 32, 4, 9, 21, 50, 64, 4, 9, 21, 51, 120, 128, 4, 9, 21, 51, 127, 289, 256, 4, 9, 21, 51, 127, 323, 697, 512, 4, 9, 21, 51, 127, 324, 835, 1682, 1024, 4, 9, 21, 51, 127, 324, 844, 2187, 4060, 2048, 4, 9, 21, 51, 127, 324, 844, 2242, 5787, 9801, 4096, 4
Offset: 1

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Author

R. H. Hardin, Jun 08 2014

Keywords

Comments

Table starts
....4....4.....4.....4.....4.....4.....4.....4.....4.....4.....4.....4.....4
....8....9.....9.....9.....9.....9.....9.....9.....9.....9.....9.....9.....9
...16...21....21....21....21....21....21....21....21....21....21....21....21
...32...50....51....51....51....51....51....51....51....51....51....51....51
...64..120...127...127...127...127...127...127...127...127...127...127...127
..128..289...323...324...324...324...324...324...324...324...324...324...324
..256..697...835...844...844...844...844...844...844...844...844...844...844
..512.1682..2187..2242..2243..2243..2243..2243..2243..2243..2243..2243..2243
.1024.4060..5787..6062..6073..6073..6073..6073..6073..6073..6073..6073..6073
.2048.9801.15435.16655.16736.16737.16737.16737.16737.16737.16737.16737.16737

Examples

			Some solutions for n=6 k=4
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
..1....0....0....0....1....1....0....0....0....0....1....1....0....1....1....0
..1....1....1....0....1....0....0....0....1....1....1....0....0....1....1....1
..1....1....0....1....1....0....1....0....0....1....2....0....1....2....2....1
..2....2....0....0....0....0....0....0....0....2....1....1....1....2....2....0
..2....1....1....1....1....1....0....0....0....1....1....1....0....1....3....1
..3....1....1....1....0....0....0....0....1....1....1....1....0....1....3....1
..2....2....1....1....1....1....0....1....1....1....0....0....2....2....0....0
		

Crossrefs

Column 1 is A000079(n+1)
Column 2 is A024537(n+1)
Column 3 is A094286(n+2)

Formula

Empirical for column k:
k=1: a(n) = 2*a(n-1)
k=2: a(n) = 3*a(n-1) -a(n-2) -a(n-3)
k=3: a(n) = 5*a(n-1) -6*a(n-2) -2*a(n-3) +4*a(n-4)
k=4: a(n) = 7*a(n-1) -14*a(n-2) +21*a(n-4) -7*a(n-5) -6*a(n-6)
k=5: [order 8]
k=6: [order 10]
k=7: [order 12]
k=8: [order 14]
k=9: [order 16]