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A203920 Number of (n+2)X7 0..1 arrays with every 3X3 subblock having equal diagonal elements or equal antidiagonal elements, and new values 0..1 introduced in row major order 1
17800, 77618, 267066, 916658, 3191760, 11082632, 38569884, 134316050, 467816690, 1629405698, 5667390680, 19715419592, 68594753068, 238634097858, 830238632478, 2888535915458, 10050627740076, 34970754257408, 121674300182928 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 5 of A203923

LINKS

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

FORMULA

Empirical: a(n) = 3*a(n-1) +2*a(n-3) +4*a(n-4) +24*a(n-5) -104*a(n-6) +366*a(n-7) +562*a(n-8) -1092*a(n-9) +892*a(n-10) +1032*a(n-11) -1064*a(n-12) -6270*a(n-13) +1420*a(n-14) +6282*a(n-15) -30476*a(n-16) +12300*a(n-17) +27280*a(n-18) -11250*a(n-19) +8350*a(n-20) -1500*a(n-21) -1000*a(n-22) +8125*a(n-24) -3125*a(n-25) for n>26

EXAMPLE

Some solutions for n=3

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

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

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

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

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

CROSSREFS

Sequence in context: A237776 A151744 A250333 * A236649 A054472 A204742

Adjacent sequences:  A203917 A203918 A203919 * A203921 A203922 A203923

KEYWORD

nonn

AUTHOR

R. H. Hardin Jan 07 2012

STATUS

approved

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Last modified July 1 03:30 EDT 2022. Contains 354947 sequences. (Running on oeis4.)