login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A252680 Number of (1+2)X(n+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 0 2 5 6 or 7 and every 3X3 column and antidiagonal sum not equal to 0 2 5 6 or 7 1
656, 775, 901, 1246, 1802, 2564, 3654, 6075, 9691, 14591, 25932, 43618, 66923, 122615, 210754, 325664, 604389, 1048008, 1624634, 3031099, 5275727, 8191512, 15312997, 26698487, 41493532, 77612674, 135438545, 210636520, 393990535 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 1 of A252679

LINKS

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

FORMULA

Empirical: a(n) = 18*a(n-3) +a(n-4) -130*a(n-6) -15*a(n-7) +490*a(n-9) +80*a(n-10) -a(n-11) -1052*a(n-12) -161*a(n-13) +15*a(n-14) +1290*a(n-15) -53*a(n-16) -89*a(n-17) -794*a(n-18) +766*a(n-19) +268*a(n-20) +55*a(n-21) -1310*a(n-22) -426*a(n-23) +220*a(n-24) +935*a(n-25) +310*a(n-26) -101*a(n-27) -138*a(n-28) +9*a(n-30) -209*a(n-31) -141*a(n-32) -24*a(n-33) +124*a(n-34) +84*a(n-35) +20*a(n-36) -20*a(n-37) -20*a(n-38) for n>48

EXAMPLE

Some solutions for n=4

..1..2..3..0..3..3....1..0..1..1..0..1....3..2..0..0..2..0....1..3..2..2..3..0

..0..0..0..0..2..0....0..0..2..0..0..2....3..0..2..0..0..2....3..1..1..0..1..1

..0..1..1..3..3..0....3..1..1..3..1..1....3..2..2..3..2..2....0..0..0..2..0..3

CROSSREFS

Sequence in context: A252671 A252672 A252679 * A233898 A088894 A015277

Adjacent sequences:  A252677 A252678 A252679 * A252681 A252682 A252683

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 20 2014

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified November 29 01:40 EST 2021. Contains 349416 sequences. (Running on oeis4.)