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.

A241356 T(n,k) = Number of n X k 0..3 arrays with no element equal to zero plus the sum of elements to its left or one plus the sum of the elements above it or one plus the sum of the elements diagonally to its northwest or zero plus the sum of the elements antidiagonally to its northeast, modulo 4.

Original entry on oeis.org

2, 2, 3, 4, 3, 4, 6, 9, 3, 7, 8, 17, 19, 4, 10, 14, 23, 51, 55, 5, 15, 20, 53, 61, 128, 72, 5, 24, 30, 103, 230, 228, 248, 124, 7, 35, 48, 160, 641, 1721, 615, 624, 243, 8, 54, 70, 344, 960, 5663, 6307, 2062, 1323, 370, 9, 83, 108, 643, 3746, 11909, 32942, 35880, 6380, 2715
Offset: 1

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Author

R. H. Hardin, Apr 20 2014

Keywords

Comments

Table starts
..2..2...4.....6......8.......14........20.........30.........48.........70
..3..3...9....17.....23.......53.......103........160........344........643
..4..3..19....51.....61......230.......641........960.......3746.......9339
..7..4..55...128....228.....1721......5663......11909......69946.....220363
.10..5..72...248....615.....6307.....32942......81541.....704210....3476469
.15..5.124...624...2062....35880....247664.....921726...10840453...85630246
.24..7.243..1323...6380...183400...1904754...10693549..198803445.2384535274
.35..8.370..2715..17325...763750..12340892..109041097.3042023002
.54..9.695..5798..60671..4110488.104529676.1490516896
.83.12.956.11469.174659.18352240.729080777

Examples

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

Crossrefs

Column 1 is A159288(n+1).
Column 2 is A226503(n+8).
Row 1 is A239851.

Formula

Empirical for column k:
k=1: a(n) = a(n-2) +2*a(n-3).
k=2: a(n) = a(n-3) +a(n-5).
k=3: [order 68] for n > 85.
Empirical for row n:
n=1: a(n) = a(n-2) +2*a(n-3).
n=2: [order 17] for n > 20.