The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A272954 Number of nX4 0..1 arrays with exactly n+4-2 having value 1 and no three 1s forming an isosceles right triangle. 1
 4, 21, 24, 60, 210, 637, 1840, 5792, 18556, 54034, 160246, 499140, 1501706, 4627363, 13954490, 43064736, 131174878, 399170874, 1222825766, 3739040310, 11456400210, 35068696769, 107362206600, 329271410590, 1009129910706, 3096269613087 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Column 4 of A272958. LINKS R. H. Hardin, Table of n, a(n) for n = 1..110 EXAMPLE Some solutions for n=5 ..0..1..1..0. .1..0..0..1. .0..0..1..1. .0..1..1..1. .1..0..1..0 ..1..0..0..1. .0..1..1..0. .0..0..0..0. .0..0..0..0. .0..0..0..1 ..0..0..0..0. .0..0..0..0. .1..0..0..1. .0..0..1..0. .0..0..0..1 ..1..0..0..1. .0..0..0..0. .1..0..1..0. .0..0..0..1. .0..0..1..0 ..0..1..0..0. .1..0..1..1. .1..0..0..0. .0..1..0..1. .1..1..0..0 CROSSREFS Cf. A272958. Sequence in context: A138228 A303722 A305225 * A133784 A041821 A042429 Adjacent sequences: A272951 A272952 A272953 * A272955 A272956 A272957 KEYWORD nonn AUTHOR R. H. Hardin, May 11 2016 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified February 7 02:40 EST 2023. Contains 360111 sequences. (Running on oeis4.)