A257420 Number of (n+2)X(2+2) 0..1 arrays with every 3X3 subblock diagonal sum plus antidiagonal minimum nondecreasing horizontally, vertically and ne-to-sw antidiagonally

2616, 7652, 30309, 119393, 403951, 1293242, 4098078, 12497488, 37528750, 111339861, 326552920, 949466125, 2746182574, 7900552664, 22633690594, 64617935573, 183950154022, 522353720305, 1480269737481, 4187439072469

Offset

1,1

Comments

Column 2 of A257426

Links

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

Formula

Empirical: a(n) = 8*a(n-1) -22*a(n-2) +19*a(n-3) +18*a(n-4) -51*a(n-5) +72*a(n-6) -170*a(n-7) +350*a(n-8) -290*a(n-9) -175*a(n-10) +299*a(n-11) +215*a(n-12) +328*a(n-13) -2659*a(n-14) +3621*a(n-15) -1361*a(n-16) -1414*a(n-17) +3863*a(n-18) -5433*a(n-19) +3704*a(n-20) -1335*a(n-21) +42*a(n-22) +1911*a(n-23) -3043*a(n-24) +3082*a(n-25) -2396*a(n-26) +1173*a(n-27) -1060*a(n-28) +488*a(n-29) +1217*a(n-30) -1835*a(n-31) +1483*a(n-32) -954*a(n-33) +223*a(n-34) +245*a(n-35) -225*a(n-36) +128*a(n-37) -173*a(n-38) +179*a(n-39) -93*a(n-40) +23*a(n-41) +2*a(n-42) -8*a(n-43) +13*a(n-44) -13*a(n-45) +6*a(n-46) -a(n-47) for n>56

Example

Some solutions for n=4
..0..1..0..0....0..1..0..0....0..0..0..1....0..0..1..1....0..1..1..1
..1..1..1..1....0..0..0..0....0..0..0..1....0..1..0..0....0..1..0..0
..0..1..0..0....1..0..0..0....1..0..1..1....0..0..0..1....0..1..0..1
..0..1..0..1....0..0..1..1....1..0..1..1....1..1..1..0....1..1..1..1
..0..1..1..1....0..1..0..0....0..1..1..0....1..1..1..0....1..1..1..1
..1..1..1..0....0..0..0..1....0..1..0..0....0..1..0..0....1..1..1..1

Crossrefs

Cf. A257426

Sequence in context: A235777 A235557 A257427 * A254236 A252440 A066871

Adjacent sequences: A257417 A257418 A257419 * A257421 A257422 A257423

Keyword

nonn

Author

R. H. Hardin, Apr 22 2015

Status

approved