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A272973 T(n,k)=Number of nXk 0..1 arrays with exactly n+k-2 having value 1 and no three 1s forming an isosceles triangle. 8
1, 2, 2, 3, 6, 3, 4, 10, 10, 4, 5, 21, 12, 21, 5, 6, 14, 4, 4, 14, 6, 7, 28, 14, 8, 14, 28, 7, 8, 18, 36, 4, 4, 36, 18, 8, 9, 29, 23, 37, 4, 37, 23, 29, 9, 10, 22, 44, 8, 4, 4, 8, 44, 22, 10, 11, 32, 14, 44, 10, 8, 10, 44, 14, 32, 11, 12, 26, 48, 8, 80, 4, 4, 80, 8, 48, 26, 12, 13, 36, 14, 44 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Table starts

..1..2..3..4..5..6..7..8..9.10.11..12.13.14.15.16.17

..2..6.10.21.14.28.18.29.22.32.26..36.30.40.34.44

..3.10.12..4.14.36.23.44.14.48.14..52.14.56.16

..4.21..4..8..4.37..8.44..8.44..0..34..4.44

..5.14.14..4..4..4.10.80.37.56..4..12..0

..6.28.36.37..4..8..4.22..0.34.32.203

..7.18.23..8.10..4..4..4..2.48.24

..8.29.44.44.80.22..4..8.16

..9.22.14..8.37..0..2.16

.10.32.48.44.56.34.48

.11.26.14..0..4.32

.12.36.52.34.12

.13.30.14..4

.14.40.56

.15.34

.16

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..143

FORMULA

Empirical for column k:

k=1: a(n) = 2*a(n-1) -a(n-2)

k=2: a(n) = a(n-1) +a(n-2) -a(n-3) for n>11

EXAMPLE

All solutions for n=3 k=4

..0..0..0..1. .1..0..0..0. .1..1..1..0. .0..1..1..1

..0..0..0..1. .1..0..0..0. .0..0..0..1. .1..0..0..0

..1..1..1..0. .0..1..1..1. .0..0..0..1. .1..0..0..0

CROSSREFS

Sequence in context: A322744 A128228 A190098 * A272958 A290632 A291543

Adjacent sequences:  A272970 A272971 A272972 * A272974 A272975 A272976

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin, May 11 2016

STATUS

approved

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Last modified October 15 00:14 EDT 2019. Contains 328025 sequences. (Running on oeis4.)