A272974 - OEIS

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A272974

T(n,k)=Number of nXk 0..1 arrays with exactly n+k-1 having value 1 and no three 1s forming an isosceles triangle.

1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1, 1, 0, 3, 0, 0, 3, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 2, 0, 0, 0, 0, 2, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 2, 0, 4, 0, 0, 4, 0, 2, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 2, 0, 2, 0, 0, 0, 0, 2, 0, 2, 0, 1, 1, 0, 0

(list; table; graph; refs; listen; history; text; internal format)

OFFSET

1,31

COMMENTS

Table starts

.1.1.1.1.1.1.1.1.1.1.1.1.1.1.1.1.1

.1.0.1.0.0.0.0.0.0.0.0.0.0.0.0.0

.1.1.0.0.0.3.0.2.0.2.0.2.0.2.0

.1.0.0.0.0.0.0.0.0.0.0.0.0.0

.1.0.0.0.0.0.0.4.0.2.0.0.0

.1.0.3.0.0.0.0.0.0.0.1.8

.1.0.0.0.0.0.0.0.0.3.0

.1.0.2.0.4.0.0.0.1

.1.0.0.0.0.0.0.1

.1.0.2.0.2.0.3

.1.0.0.0.0.1

.1.0.2.0.0

.1.0.0.0

.1.0.2

.1.0

LINKS

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

FORMULA

Row n extended:

n=2: 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

n=3: 1 1 0 0 0 3 0 2 0 2 0 2 0 2 0 2 0 2 0 2 0 2

n=4: 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

n=5: 1 0 0 0 0 0 0 4 0 2 0 0 0 0 0

n=6: 1 0 3 0 0 0 0 0 0 0 1 8 0

EXAMPLE

All solutions for n=3 k=6

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

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

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

CROSSREFS

Sequence in context: A284444 A341794 A033685 * A063691 A359967 A284281

Adjacent sequences: A272971 A272972 A272973 * A272975 A272976 A272977

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin, May 11 2016

STATUS

approved