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.

A242239 T(n,k)=Number of length n+k+1 0..k arrays with every value 0..k appearing at least once in every consecutive k+2 elements, and new values 0..k introduced in order.

Original entry on oeis.org

3, 6, 5, 10, 12, 8, 15, 22, 22, 13, 21, 35, 43, 40, 21, 28, 51, 71, 82, 74, 34, 36, 70, 106, 139, 157, 136, 55, 45, 92, 148, 211, 271, 304, 250, 89, 55, 117, 197, 298, 416, 531, 586, 460, 144, 66, 145, 253, 400, 592, 821, 1047, 1129, 846, 233, 78, 176, 316, 517, 799
Offset: 1

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Author

R. H. Hardin, May 08 2014

Keywords

Comments

Table starts
...3....6...10...15....21....28....36....45....55....66....78....91...105
...5...12...22...35....51....70....92...117...145...176...210...247...287
...8...22...43...71...106...148...197...253...316...386...463...547...638
..13...40...82..139...211...298...400...517...649...796...958..1135..1327
..21...74..157..271...416...592...799..1037..1306..1606..1937..2299..2692
..34..136..304..531...821..1174..1590..2069..2611..3216..3884..4615..5409
..55..250..586.1047..1626..2332..3165..4125..5212..6426..7767..9235.10830
..89..460.1129.2059..3231..4642..6308..8229.10405.12836.15522.18463.21659
.144..846.2176.4047..6411..9256.12587.16429.20782.25646.31021.36907.43304
.233.1556.4195.7955.12716.18442.25138.32821.41527.51256.62008.73783.86581

Examples

			Some solutions for n=5 k=4
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
..1....1....1....1....1....1....1....1....1....1....1....1....1....0....1....1
..2....2....0....2....2....1....0....0....2....0....2....2....0....1....2....0
..1....3....2....3....3....2....2....2....3....2....3....3....2....2....3....2
..3....4....3....4....4....3....3....3....0....3....0....0....3....3....4....3
..4....0....4....1....0....4....4....4....4....4....4....4....4....4....1....4
..0....2....2....0....1....0....2....0....2....1....2....1....0....2....0....1
..2....1....1....0....2....1....1....1....1....0....1....2....1....0....2....0
..2....3....0....2....3....0....0....1....0....0....3....4....2....1....3....4
..1....0....0....3....0....2....2....2....3....2....2....3....3....1....0....2
		

Crossrefs

Column 1 is A000045(n+3)
Column 2 is A196700(n+3)
Row 1 is A000217(n+1)
Row 2 is A000326(n+1)
Row 3 is A069099(n+1)
Row 4 is A220083

Formula

Empirical for column k:
k=1: a(n) = a(n-1) +a(n-2)
k=2: a(n) = a(n-1) +a(n-2) +a(n-3)
k=3: a(n) = a(n-1) +a(n-2) +a(n-3) +a(n-4)
k=4: a(n) = a(n-1) +a(n-2) +a(n-3) +a(n-4) +a(n-5)
k=5: a(n) = a(n-1) +a(n-2) +a(n-3) +a(n-4) +a(n-5) +a(n-6)
k=6: a(n) = a(n-1) +a(n-2) +a(n-3) +a(n-4) +a(n-5) +a(n-6) +a(n-7)
k=7: a(n) = a(n-1) +a(n-2) +a(n-3) +a(n-4) +a(n-5) +a(n-6) +a(n-7) +a(n-8)
k=8: a(n) = a(n-1) +a(n-2) +a(n-3) +a(n-4) +a(n-5) +a(n-6) +a(n-7) +a(n-8) +a(n-9)
k=9: a(n) = a(n-1) +a(n-2) +a(n-3) +a(n-4) +a(n-5) +a(n-6) +a(n-7) +a(n-8) +a(n-9) +a(n-10)
Empirical for row n:
n=1: a(n) = (1/2)*n^2 + (3/2)*n + 1
n=2: a(n) = (3/2)*n^2 + (5/2)*n + 1
n=3: a(n) = (7/2)*n^2 + (7/2)*n + 1
n=4: a(n) = (15/2)*n^2 + (9/2)*n + 1
n=5: a(n) = (31/2)*n^2 + (11/2)*n + 1 for n>1
n=6: a(n) = (63/2)*n^2 + (13/2)*n + 1 for n>2
n=7: a(n) = (127/2)*n^2 + (15/2)*n + 1 for n>3
n=8: a(n) = (255/2)*n^2 + (17/2)*n + 1 for n>4
n=9: a(n) = (511/2)*n^2 + (19/2)*n + 1 for n>5
n=10: a(n) = (1023/2)*n^2 + (21/2)*n + 1 for n>6
n=11: a(n) = (2047/2)*n^2 + (23/2)*n + 1 for n>7
n=12: a(n) = (4095/2)*n^2 + (25/2)*n + 1 for n>8
n=13: a(n) = (8191/2)*n^2 + (27/2)*n + 1 for n>9
n=14: a(n) = (16383/2)*n^2 + (29/2)*n + 1 for n>10
n=15: a(n) = (32767/2)*n^2 + (31/2)*n + 1 for n>11
Empirical large-k generalization, for k>n-4: T(n,k) = ((2^n-1)/2)*k^2 + ((2*n+1)/2)*k + 1
Empirical recurrence generalization, for column k: a(n) = sum {i in 1..k+1} a(n-i)