A252392 Number of (n+2)X(1+2) 0..2 arrays with every 3X3 subblock row, column, diagonal and antidiagonal sum less than 4

2205, 21544, 224346, 2302050, 23364738, 237415904, 2418956843, 24645111392, 250920865658, 2554769901375, 26015822760712, 264922289636340, 2697637825459030, 27469479857851894, 279718150473560850

Offset

1,1

Comments

Column 1 of A252397

Links

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

Formula

Empirical: a(n) = 8*a(n-1) +234*a(n-3) +24*a(n-4) -134*a(n-5) -8950*a(n-6) -9350*a(n-7) +49283*a(n-8) +210162*a(n-9) -39046*a(n-10) -1502624*a(n-11) -961458*a(n-12) +4176954*a(n-13) +8490842*a(n-14) -8133955*a(n-15) -14842568*a(n-16) +7277569*a(n-17) -4965301*a(n-18) -3759488*a(n-19) +14794041*a(n-20) +9897921*a(n-21) +6346963*a(n-22) +12778436*a(n-23) +856026*a(n-24) -5366660*a(n-25) +24416*a(n-26) -10411883*a(n-27) -5843788*a(n-28) -526458*a(n-29) +1188054*a(n-30) -2715931*a(n-31) +1188891*a(n-32) +1461378*a(n-33) -330832*a(n-34) -151531*a(n-35) +184588*a(n-36) +24800*a(n-37) -22912*a(n-38) -4096*a(n-39) for n>45

Example

Some solutions for n=2
..0..0..2....1..0..1....2..0..0....0..2..0....0..0..0....1..0..0....0..0..1
..0..0..0....0..0..2....0..0..1....1..0..1....0..1..1....0..0..1....0..1..1
..1..1..1....0..0..0....0..0..0....0..0..0....0..1..1....0..1..2....1..0..0
..1..1..0....1..0..0....0..1..2....0..2..1....0..0..0....1..1..0....0..0..1

Crossrefs

Sequence in context: A125015 A348743 A252397 * A175915 A098192 A004931

Adjacent sequences: A252389 A252390 A252391 * A252393 A252394 A252395

Keyword

nonn

Author

R. H. Hardin, Dec 17 2014

Status

approved