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.

A212835 T(n,k)=Number of 0..k arrays of length n+1 with 0 never adjacent to k.

Original entry on oeis.org

2, 7, 2, 14, 17, 2, 23, 50, 41, 2, 34, 107, 178, 99, 2, 47, 194, 497, 634, 239, 2, 62, 317, 1106, 2309, 2258, 577, 2, 79, 482, 2137, 6306, 10727, 8042, 1393, 2, 98, 695, 3746, 14407, 35954, 49835, 28642, 3363, 2, 119, 962, 6113, 29114, 97127, 204994, 231521
Offset: 1

Views

Author

R. H. Hardin May 28 2012

Keywords

Comments

Table starts
.2.....7......14.......23........34.........47.........62..........79
.2....17......50......107.......194........317........482.........695
.2....41.....178......497......1106.......2137.......3746........6113
.2....99.....634.....2309......6306......14407......29114.......53769
.2...239....2258....10727.....35954......97127.....226274......472943
.2...577....8042....49835....204994.....654797....1758602.....4159927
.2..1393...28642...231521...1168786....4414417...13667858....36590017
.2..3363..102010..1075589...6663906...29760487..106226618...321839625
.2..8119..363314..4996919..37994674..200635007..825593474..2830847119
.2.19601.1293962.23214443.216628994.1352612477.6416514026.24899654327

Examples

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

Crossrefs

Column 2 is A001333(n+2)
Column 3 is A055099(n+1)
Column 4 is A126473(n+1)
Column 5 is A126501(n+1)
Column 6 is A126528(n+1)
Row 1 is A008865(n+1)

Formula

Empirical for column k: a(n) = k*a(n-1) +(k-1)*a(n-2)
Empirical for rows:
n=1: a(k) = k^2 + 2*k - 1
n=2: a(k) = k^3 + 3*k^2 - k - 1
n=3: a(k) = k^4 + 4*k^3 - 4*k + 1
n=4: a(k) = k^5 + 5*k^4 + 2*k^3 - 8*k^2 + k + 1
n=5: a(k) = k^6 + 6*k^5 + 5*k^4 - 12*k^3 - 3*k^2 + 6*k - 1
n=6: a(k) = k^7 + 7*k^6 + 9*k^5 - 15*k^4 - 13*k^3 + 15*k^2 - k - 1
n=7: a(k) = k^8 + 8*k^7 + 14*k^6 - 16*k^5 - 30*k^4 + 24*k^3 + 8*k^2 - 8*k + 1