login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A251822
Number of (n+2)X(1+2) 0..3 arrays with every 3X3 subblock row and column sum not 3 or 6 and every diagonal and antidiagonal sum 3 or 6
1
1890, 3930, 9354, 22266, 61058, 160322, 413202, 1139826, 3118482, 8319882, 23584586, 65465226, 178084738, 504244530, 1412258994, 3880043794, 11020794162, 30982240178, 85749834586, 243381206194, 686186919786, 1908589426914
OFFSET
1,1
COMMENTS
Column 1 of A251829
LINKS
FORMULA
Empirical: a(n) = a(n-1) +14*a(n-2) +30*a(n-3) -115*a(n-4) -518*a(n-5) +205*a(n-6) +3196*a(n-7) +3904*a(n-8) -13120*a(n-9) -23920*a(n-10) +46793*a(n-11) +87720*a(n-12) -170294*a(n-13) -600803*a(n-14) +572580*a(n-15) +2805533*a(n-16) -92853*a(n-17) -7293684*a(n-18) -5964065*a(n-19) +18744915*a(n-20) +12066358*a(n-21) -50001398*a(n-22) -41225930*a(n-23) +91954292*a(n-24) +244645926*a(n-25) -77530458*a(n-26) -435940304*a(n-27) -315905492*a(n-28) +96427640*a(n-29) +838056696*a(n-30) +362622920*a(n-31) +136187880*a(n-32) -941451568*a(n-33) -1040264336*a(n-34) +753366048*a(n-35) +369089152*a(n-36) +226212288*a(n-37) +312962048*a(n-38) -608963328*a(n-39) -257748480*a(n-40) +322808832*a(n-41) +66686976*a(n-42) -72161280*a(n-43) -5971968*a(n-44) +5971968*a(n-45) for n>48
EXAMPLE
Some solutions for n=4
..3..0..1....2..2..3....1..3..1....0..0..0....0..2..0....0..0..1....3..0..1
..2..2..3....3..0..1....0..2..0....1..0..1....1..0..1....2..2..3....2..0..0
..0..3..1....3..0..1....3..2..0....3..2..3....3..2..3....0..0..1....2..0..0
..0..3..1....2..2..0....1..0..1....0..2..3....3..2..0....0..3..1....3..0..1
..2..2..3....0..0..1....3..2..3....1..0..1....1..0..1....2..2..3....3..0..1
..3..3..1....3..0..1....0..2..3....3..2..3....3..2..3....3..0..1....2..0..3
CROSSREFS
Sequence in context: A151721 A187743 A251829 * A251821 A151773 A020321
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 09 2014
STATUS
approved