A203920 - OEIS

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

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