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A272953 Number of nX3 0..1 arrays with exactly n+3-2 having value 1 and no three 1s forming an isosceles right triangle. 1
3, 10, 24, 24, 107, 236, 499, 1228, 2753, 6292, 14751, 34824, 78495, 179600, 418135, 958972, 2193399, 5026564, 11504714, 26279352, 60040180, 137016314, 312081316, 710648768, 1617618343, 3678123154, 8356175747, 18974024164, 43057072946 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 3 of A272958.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = 6*a(n-1) -15*a(n-2) +26*a(n-3) -30*a(n-4) -6*a(n-5) +71*a(n-6) -144*a(n-7) +168*a(n-8) +94*a(n-9) -469*a(n-10) +652*a(n-11) -378*a(n-12) -1158*a(n-13) +2908*a(n-14) -3158*a(n-15) +1005*a(n-16) +4842*a(n-17) -10378*a(n-18) +8764*a(n-19) +1617*a(n-20) -16040*a(n-21) +24082*a(n-22) -14472*a(n-23) -15317*a(n-24) +45188*a(n-25) -49946*a(n-26) +26510*a(n-27) +22275*a(n-28) -82222*a(n-29) +110930*a(n-30) -74226*a(n-31) -14272*a(n-32) +113348*a(n-33) -178337*a(n-34) +141136*a(n-35) +7266*a(n-36) -149432*a(n-37) +185895*a(n-38) -129140*a(n-39) +22038*a(n-40) +101372*a(n-41) -166288*a(n-42) +124584*a(n-43) -34773*a(n-44) -55018*a(n-45) +132927*a(n-46) -129638*a(n-47) +12757*a(n-48) +101176*a(n-49) -91095*a(n-50) +8640*a(n-51) +38603*a(n-52) -32838*a(n-53) +3964*a(n-54) +15224*a(n-55) -10065*a(n-56) -5948*a(n-57) +8968*a(n-58) +140*a(n-59) -4048*a(n-60) +2312*a(n-61) -236*a(n-62) -772*a(n-63) +628*a(n-64) -48*a(n-65) -252*a(n-66) -32*a(n-67) +108*a(n-68) -8*a(n-69) +12*a(n-70) +16*a(n-71) -16*a(n-72)

EXAMPLE

Some solutions for n=5

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

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

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

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

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

CROSSREFS

Cf. A272958.

Sequence in context: A228493 A041327 A231116 * A259443 A293405 A029880

Adjacent sequences:  A272950 A272951 A272952 * A272954 A272955 A272956

KEYWORD

nonn

AUTHOR

R. H. Hardin, May 11 2016

STATUS

approved

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Last modified May 24 23:45 EDT 2020. Contains 334581 sequences. (Running on oeis4.)